[llvm] [AMDGPU] Use LSH for lowering ctlz_zero_undef.i8/i16 (PR #88512)

Leon Clark via llvm-commits llvm-commits at lists.llvm.org
Fri May 17 14:38:07 PDT 2024


https://github.com/PeddleSpam updated https://github.com/llvm/llvm-project/pull/88512

>From 051846c55cc0927a5abacc235583e755cd92bab5 Mon Sep 17 00:00:00 2001
From: Leon Clark <leoclark at amd.com>
Date: Fri, 12 Apr 2024 14:15:32 +0100
Subject: [PATCH 01/11] [AMDGPU] Use LSH for lowering ctlz_zero_undef.i8/i16

---
 llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp | 19 +++--
 llvm/test/CodeGen/AMDGPU/ctlz_zero_undef.ll   | 77 +++++++++----------
 2 files changed, 52 insertions(+), 44 deletions(-)

diff --git a/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp b/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp
index d35a022ad6806..e06837a7ab517 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp
@@ -3117,20 +3117,29 @@ static bool isCttzOpc(unsigned Opc) {
 SDValue AMDGPUTargetLowering::lowerCTLZResults(SDValue Op,
                                                SelectionDAG &DAG) const {
   auto SL = SDLoc(Op);
+  auto Opc = Op.getOpcode();
   auto Arg = Op.getOperand(0u);
   auto ResultVT = Op.getValueType();
 
   if (ResultVT != MVT::i8 && ResultVT != MVT::i16)
     return {};
 
-  assert(isCtlzOpc(Op.getOpcode()));
+  assert(isCtlzOpc(Opc));
   assert(ResultVT == Arg.getValueType());
 
-  auto const LeadingZeroes = 32u - ResultVT.getFixedSizeInBits();
-  auto SubVal = DAG.getConstant(LeadingZeroes, SL, MVT::i32);
+  auto const NumBits = ResultVT.getFixedSizeInBits();
+  auto NumExtBits = DAG.getConstant(32u - NumBits, SL, MVT::i32);
   auto NewOp = DAG.getNode(ISD::ZERO_EXTEND, SL, MVT::i32, Arg);
-  NewOp = DAG.getNode(Op.getOpcode(), SL, MVT::i32, NewOp);
-  NewOp = DAG.getNode(ISD::SUB, SL, MVT::i32, NewOp, SubVal);
+
+  if (Opc == ISD::CTLZ_ZERO_UNDEF) {
+    NewOp = DAG.getNode(ISD::SHL, SL, MVT::i32, NewOp, NumExtBits);
+    NewOp = DAG.getNode(Opc, SL, MVT::i32, NewOp);
+  }
+  else {
+    NewOp = DAG.getNode(Opc, SL, MVT::i32, NewOp);
+    NewOp = DAG.getNode(ISD::SUB, SL, MVT::i32, NewOp, NumExtBits);
+  }
+
   return DAG.getNode(ISD::TRUNCATE, SL, ResultVT, NewOp);
 }
 
diff --git a/llvm/test/CodeGen/AMDGPU/ctlz_zero_undef.ll b/llvm/test/CodeGen/AMDGPU/ctlz_zero_undef.ll
index 54adde38d6d22..143ff5d88894b 100644
--- a/llvm/test/CodeGen/AMDGPU/ctlz_zero_undef.ll
+++ b/llvm/test/CodeGen/AMDGPU/ctlz_zero_undef.ll
@@ -322,9 +322,8 @@ define amdgpu_kernel void @s_ctlz_zero_undef_i8_with_select(ptr addrspace(1) noa
 ; SI-NEXT:    s_load_dwordx2 s[0:1], s[0:1], 0x9
 ; SI-NEXT:    s_mov_b32 s3, 0xf000
 ; SI-NEXT:    s_waitcnt lgkmcnt(0)
-; SI-NEXT:    s_and_b32 s2, s2, 0xff
-; SI-NEXT:    s_flbit_i32_b32 s2, s2
-; SI-NEXT:    s_sub_i32 s4, s2, 24
+; SI-NEXT:    s_lshl_b32 s2, s2, 24
+; SI-NEXT:    s_flbit_i32_b32 s4, s2
 ; SI-NEXT:    s_mov_b32 s2, -1
 ; SI-NEXT:    v_mov_b32_e32 v0, s4
 ; SI-NEXT:    buffer_store_byte v0, off, s[0:3], 0
@@ -335,9 +334,8 @@ define amdgpu_kernel void @s_ctlz_zero_undef_i8_with_select(ptr addrspace(1) noa
 ; VI-NEXT:    s_load_dword s2, s[0:1], 0x2c
 ; VI-NEXT:    s_load_dwordx2 s[0:1], s[0:1], 0x24
 ; VI-NEXT:    s_waitcnt lgkmcnt(0)
-; VI-NEXT:    s_and_b32 s2, s2, 0xff
+; VI-NEXT:    s_lshl_b32 s2, s2, 24
 ; VI-NEXT:    s_flbit_i32_b32 s2, s2
-; VI-NEXT:    s_sub_i32 s2, s2, 24
 ; VI-NEXT:    v_mov_b32_e32 v0, s0
 ; VI-NEXT:    v_mov_b32_e32 v1, s1
 ; VI-NEXT:    v_mov_b32_e32 v2, s2
@@ -357,13 +355,13 @@ define amdgpu_kernel void @s_ctlz_zero_undef_i8_with_select(ptr addrspace(1) noa
 ; EG-NEXT:    ALU clause starting at 8:
 ; EG-NEXT:     MOV * T0.X, 0.0,
 ; EG-NEXT:    ALU clause starting at 9:
-; EG-NEXT:     FFBH_UINT T0.W, T0.X,
+; EG-NEXT:     LSHL * T0.W, T0.X, literal.x,
+; EG-NEXT:    24(3.363116e-44), 0(0.000000e+00)
+; EG-NEXT:     FFBH_UINT T0.W, PV.W,
 ; EG-NEXT:     AND_INT * T1.W, KC0[2].Y, literal.x,
 ; EG-NEXT:    3(4.203895e-45), 0(0.000000e+00)
-; EG-NEXT:     ADD_INT * T0.W, PV.W, literal.x,
-; EG-NEXT:    -24(nan), 0(0.000000e+00)
 ; EG-NEXT:     AND_INT T0.W, PV.W, literal.x,
-; EG-NEXT:     LSHL * T1.W, T1.W, literal.y,
+; EG-NEXT:     LSHL * T1.W, PS, literal.y,
 ; EG-NEXT:    255(3.573311e-43), 3(4.203895e-45)
 ; EG-NEXT:     LSHL T0.X, PV.W, PS,
 ; EG-NEXT:     LSHL * T0.W, literal.x, PS,
@@ -399,9 +397,8 @@ define amdgpu_kernel void @s_ctlz_zero_undef_i16_with_select(ptr addrspace(1) no
 ; SI-NEXT:    s_load_dwordx2 s[0:1], s[0:1], 0x9
 ; SI-NEXT:    s_mov_b32 s3, 0xf000
 ; SI-NEXT:    s_waitcnt lgkmcnt(0)
-; SI-NEXT:    s_and_b32 s2, s2, 0xffff
-; SI-NEXT:    s_flbit_i32_b32 s2, s2
-; SI-NEXT:    s_add_i32 s4, s2, -16
+; SI-NEXT:    s_lshl_b32 s2, s2, 16
+; SI-NEXT:    s_flbit_i32_b32 s4, s2
 ; SI-NEXT:    s_mov_b32 s2, -1
 ; SI-NEXT:    v_mov_b32_e32 v0, s4
 ; SI-NEXT:    buffer_store_short v0, off, s[0:3], 0
@@ -434,13 +431,13 @@ define amdgpu_kernel void @s_ctlz_zero_undef_i16_with_select(ptr addrspace(1) no
 ; EG-NEXT:    ALU clause starting at 8:
 ; EG-NEXT:     MOV * T0.X, 0.0,
 ; EG-NEXT:    ALU clause starting at 9:
-; EG-NEXT:     FFBH_UINT T0.W, T0.X,
+; EG-NEXT:     LSHL * T0.W, T0.X, literal.x,
+; EG-NEXT:    16(2.242078e-44), 0(0.000000e+00)
+; EG-NEXT:     FFBH_UINT T0.W, PV.W,
 ; EG-NEXT:     AND_INT * T1.W, KC0[2].Y, literal.x,
 ; EG-NEXT:    3(4.203895e-45), 0(0.000000e+00)
-; EG-NEXT:     ADD_INT * T0.W, PV.W, literal.x,
-; EG-NEXT:    -16(nan), 0(0.000000e+00)
 ; EG-NEXT:     AND_INT T0.W, PV.W, literal.x,
-; EG-NEXT:     LSHL * T1.W, T1.W, literal.y,
+; EG-NEXT:     LSHL * T1.W, PS, literal.y,
 ; EG-NEXT:    65535(9.183409e-41), 3(4.203895e-45)
 ; EG-NEXT:     LSHL T0.X, PV.W, PS,
 ; EG-NEXT:     LSHL * T0.W, literal.x, PS,
@@ -598,8 +595,8 @@ define amdgpu_kernel void @v_ctlz_zero_undef_i8_with_select(ptr addrspace(1) noa
 ; SI-NEXT:    s_mov_b32 s4, s0
 ; SI-NEXT:    s_mov_b32 s5, s1
 ; SI-NEXT:    s_waitcnt vmcnt(0)
-; SI-NEXT:    v_ffbh_u32_e32 v1, v0
-; SI-NEXT:    v_subrev_i32_e32 v1, vcc, 24, v1
+; SI-NEXT:    v_lshlrev_b32_e32 v1, 24, v0
+; SI-NEXT:    v_ffbh_u32_e32 v1, v1
 ; SI-NEXT:    v_cmp_ne_u32_e32 vcc, 0, v0
 ; SI-NEXT:    v_cndmask_b32_e32 v0, 32, v1, vcc
 ; SI-NEXT:    buffer_store_byte v0, off, s[4:7], 0
@@ -613,8 +610,8 @@ define amdgpu_kernel void @v_ctlz_zero_undef_i8_with_select(ptr addrspace(1) noa
 ; VI-NEXT:    v_mov_b32_e32 v1, s3
 ; VI-NEXT:    flat_load_ubyte v0, v[0:1]
 ; VI-NEXT:    s_waitcnt vmcnt(0)
-; VI-NEXT:    v_ffbh_u32_sdwa v1, v0 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:WORD_0
-; VI-NEXT:    v_subrev_u32_e32 v1, vcc, 24, v1
+; VI-NEXT:    v_lshlrev_b32_e32 v1, 24, v0
+; VI-NEXT:    v_ffbh_u32_e32 v1, v1
 ; VI-NEXT:    v_cmp_ne_u16_e32 vcc, 0, v0
 ; VI-NEXT:    v_cndmask_b32_e32 v2, 32, v1, vcc
 ; VI-NEXT:    v_mov_b32_e32 v0, s0
@@ -626,7 +623,7 @@ define amdgpu_kernel void @v_ctlz_zero_undef_i8_with_select(ptr addrspace(1) noa
 ; EG:       ; %bb.0:
 ; EG-NEXT:    ALU 0, @8, KC0[CB0:0-32], KC1[]
 ; EG-NEXT:    TEX 0 @6
-; EG-NEXT:    ALU 15, @9, KC0[CB0:0-32], KC1[]
+; EG-NEXT:    ALU 16, @9, KC0[CB0:0-32], KC1[]
 ; EG-NEXT:    MEM_RAT MSKOR T0.XW, T1.X
 ; EG-NEXT:    CF_END
 ; EG-NEXT:    PAD
@@ -635,10 +632,11 @@ define amdgpu_kernel void @v_ctlz_zero_undef_i8_with_select(ptr addrspace(1) noa
 ; EG-NEXT:    ALU clause starting at 8:
 ; EG-NEXT:     MOV * T0.X, KC0[2].Z,
 ; EG-NEXT:    ALU clause starting at 9:
-; EG-NEXT:     FFBH_UINT * T0.W, T0.X,
-; EG-NEXT:     ADD_INT T0.W, PV.W, literal.x,
-; EG-NEXT:     AND_INT * T1.W, KC0[2].Y, literal.y,
-; EG-NEXT:    -24(nan), 3(4.203895e-45)
+; EG-NEXT:     LSHL * T0.W, T0.X, literal.x,
+; EG-NEXT:    24(3.363116e-44), 0(0.000000e+00)
+; EG-NEXT:     FFBH_UINT T0.W, PV.W,
+; EG-NEXT:     AND_INT * T1.W, KC0[2].Y, literal.x,
+; EG-NEXT:    3(4.203895e-45), 0(0.000000e+00)
 ; EG-NEXT:     CNDE_INT * T0.W, T0.X, literal.x, PV.W,
 ; EG-NEXT:    32(4.484155e-44), 0(0.000000e+00)
 ; EG-NEXT:     AND_INT T0.W, PV.W, literal.x,
@@ -693,8 +691,8 @@ define amdgpu_kernel void @v_ctlz_zero_undef_i16_with_select(ptr addrspace(1) no
 ; SI-NEXT:    v_lshlrev_b32_e32 v0, 8, v0
 ; SI-NEXT:    s_waitcnt vmcnt(0)
 ; SI-NEXT:    v_or_b32_e32 v0, v0, v1
-; SI-NEXT:    v_ffbh_u32_e32 v1, v0
-; SI-NEXT:    v_add_i32_e32 v1, vcc, -16, v1
+; SI-NEXT:    v_lshlrev_b32_e32 v1, 16, v0
+; SI-NEXT:    v_ffbh_u32_e32 v1, v1
 ; SI-NEXT:    v_cmp_ne_u32_e32 vcc, 0, v0
 ; SI-NEXT:    v_cndmask_b32_e32 v0, 32, v1, vcc
 ; SI-NEXT:    buffer_store_short v0, off, s[4:7], 0
@@ -729,7 +727,7 @@ define amdgpu_kernel void @v_ctlz_zero_undef_i16_with_select(ptr addrspace(1) no
 ; EG:       ; %bb.0:
 ; EG-NEXT:    ALU 0, @8, KC0[CB0:0-32], KC1[]
 ; EG-NEXT:    TEX 0 @6
-; EG-NEXT:    ALU 15, @9, KC0[CB0:0-32], KC1[]
+; EG-NEXT:    ALU 16, @9, KC0[CB0:0-32], KC1[]
 ; EG-NEXT:    MEM_RAT MSKOR T0.XW, T1.X
 ; EG-NEXT:    CF_END
 ; EG-NEXT:    PAD
@@ -738,10 +736,11 @@ define amdgpu_kernel void @v_ctlz_zero_undef_i16_with_select(ptr addrspace(1) no
 ; EG-NEXT:    ALU clause starting at 8:
 ; EG-NEXT:     MOV * T0.X, KC0[2].Z,
 ; EG-NEXT:    ALU clause starting at 9:
-; EG-NEXT:     FFBH_UINT * T0.W, T0.X,
-; EG-NEXT:     ADD_INT T0.W, PV.W, literal.x,
-; EG-NEXT:     AND_INT * T1.W, KC0[2].Y, literal.y,
-; EG-NEXT:    -16(nan), 3(4.203895e-45)
+; EG-NEXT:     LSHL * T0.W, T0.X, literal.x,
+; EG-NEXT:    16(2.242078e-44), 0(0.000000e+00)
+; EG-NEXT:     FFBH_UINT T0.W, PV.W,
+; EG-NEXT:     AND_INT * T1.W, KC0[2].Y, literal.x,
+; EG-NEXT:    3(4.203895e-45), 0(0.000000e+00)
 ; EG-NEXT:     CNDE_INT * T0.W, T0.X, literal.x, PV.W,
 ; EG-NEXT:    32(4.484155e-44), 0(0.000000e+00)
 ; EG-NEXT:     AND_INT T0.W, PV.W, literal.x,
@@ -1110,8 +1109,8 @@ define amdgpu_kernel void @v_ctlz_zero_undef_i8(ptr addrspace(1) noalias %out, p
 ; SI-NEXT:    s_mov_b32 s4, s0
 ; SI-NEXT:    s_mov_b32 s5, s1
 ; SI-NEXT:    s_waitcnt vmcnt(0)
+; SI-NEXT:    v_lshlrev_b32_e32 v0, 24, v0
 ; SI-NEXT:    v_ffbh_u32_e32 v0, v0
-; SI-NEXT:    v_subrev_i32_e32 v0, vcc, 24, v0
 ; SI-NEXT:    buffer_store_byte v0, off, s[4:7], 0
 ; SI-NEXT:    s_endpgm
 ;
@@ -1124,8 +1123,8 @@ define amdgpu_kernel void @v_ctlz_zero_undef_i8(ptr addrspace(1) noalias %out, p
 ; VI-NEXT:    v_addc_u32_e32 v1, vcc, 0, v1, vcc
 ; VI-NEXT:    flat_load_ubyte v0, v[0:1]
 ; VI-NEXT:    s_waitcnt vmcnt(0)
-; VI-NEXT:    v_ffbh_u32_e32 v0, v0
-; VI-NEXT:    v_subrev_u32_e32 v2, vcc, 24, v0
+; VI-NEXT:    v_lshlrev_b32_e32 v0, 24, v0
+; VI-NEXT:    v_ffbh_u32_e32 v2, v0
 ; VI-NEXT:    v_mov_b32_e32 v0, s0
 ; VI-NEXT:    v_mov_b32_e32 v1, s1
 ; VI-NEXT:    flat_store_byte v[0:1], v2
@@ -1144,13 +1143,13 @@ define amdgpu_kernel void @v_ctlz_zero_undef_i8(ptr addrspace(1) noalias %out, p
 ; EG-NEXT:    ALU clause starting at 8:
 ; EG-NEXT:     ADD_INT * T0.X, KC0[2].Z, T0.X,
 ; EG-NEXT:    ALU clause starting at 9:
-; EG-NEXT:     FFBH_UINT T0.W, T0.X,
+; EG-NEXT:     LSHL * T0.W, T0.X, literal.x,
+; EG-NEXT:    24(3.363116e-44), 0(0.000000e+00)
+; EG-NEXT:     FFBH_UINT T0.W, PV.W,
 ; EG-NEXT:     AND_INT * T1.W, KC0[2].Y, literal.x,
 ; EG-NEXT:    3(4.203895e-45), 0(0.000000e+00)
-; EG-NEXT:     ADD_INT * T0.W, PV.W, literal.x,
-; EG-NEXT:    -24(nan), 0(0.000000e+00)
 ; EG-NEXT:     AND_INT T0.W, PV.W, literal.x,
-; EG-NEXT:     LSHL * T1.W, T1.W, literal.y,
+; EG-NEXT:     LSHL * T1.W, PS, literal.y,
 ; EG-NEXT:    255(3.573311e-43), 3(4.203895e-45)
 ; EG-NEXT:     LSHL T0.X, PV.W, PS,
 ; EG-NEXT:     LSHL * T0.W, literal.x, PS,

>From 6a8e358a0815e43b897f1eca33a6417c3443b520 Mon Sep 17 00:00:00 2001
From: Leon Clark <leoclark at amd.com>
Date: Fri, 12 Apr 2024 14:43:42 +0100
Subject: [PATCH 02/11] Formatting changes.

---
 llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp b/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp
index e06837a7ab517..eff5734b07b81 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp
@@ -3134,8 +3134,7 @@ SDValue AMDGPUTargetLowering::lowerCTLZResults(SDValue Op,
   if (Opc == ISD::CTLZ_ZERO_UNDEF) {
     NewOp = DAG.getNode(ISD::SHL, SL, MVT::i32, NewOp, NumExtBits);
     NewOp = DAG.getNode(Opc, SL, MVT::i32, NewOp);
-  }
-  else {
+  } else {
     NewOp = DAG.getNode(Opc, SL, MVT::i32, NewOp);
     NewOp = DAG.getNode(ISD::SUB, SL, MVT::i32, NewOp, NumExtBits);
   }

>From 5d41bdbdb65099d5d651a5261d002866efe1f1f3 Mon Sep 17 00:00:00 2001
From: Leon Clark <leoclark at amd.com>
Date: Mon, 22 Apr 2024 22:51:34 +0100
Subject: [PATCH 03/11] Add optimisations to GISel and address comments.

---
 llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp |  4 +-
 .../lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp | 50 ++++++++++++++++++-
 llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.h  |  2 +
 .../GlobalISel/legalize-ctlz-zero-undef.mir   | 33 ++++++------
 llvm/test/CodeGen/AMDGPU/ctlz_zero_undef.ll   | 24 ++++-----
 5 files changed, 77 insertions(+), 36 deletions(-)

diff --git a/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp b/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp
index eff5734b07b81..d01d0483af071 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp
@@ -3129,12 +3129,14 @@ SDValue AMDGPUTargetLowering::lowerCTLZResults(SDValue Op,
 
   auto const NumBits = ResultVT.getFixedSizeInBits();
   auto NumExtBits = DAG.getConstant(32u - NumBits, SL, MVT::i32);
-  auto NewOp = DAG.getNode(ISD::ZERO_EXTEND, SL, MVT::i32, Arg);
+  auto NewOp = SDValue();
 
   if (Opc == ISD::CTLZ_ZERO_UNDEF) {
+    NewOp = DAG.getNode(ISD::ANY_EXTEND, SL, MVT::i32, Arg);
     NewOp = DAG.getNode(ISD::SHL, SL, MVT::i32, NewOp, NumExtBits);
     NewOp = DAG.getNode(Opc, SL, MVT::i32, NewOp);
   } else {
+    NewOp = DAG.getNode(ISD::ZERO_EXTEND, SL, MVT::i32, Arg);
     NewOp = DAG.getNode(Opc, SL, MVT::i32, NewOp);
     NewOp = DAG.getNode(ISD::SUB, SL, MVT::i32, NewOp, NumExtBits);
   }
diff --git a/llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp b/llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp
index bd7bf78c4c0bd..c241522896084 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp
@@ -1270,7 +1270,30 @@ AMDGPULegalizerInfo::AMDGPULegalizerInfo(const GCNSubtarget &ST_,
     .custom();
 
   // The 64-bit versions produce 32-bit results, but only on the SALU.
-  getActionDefinitionsBuilder({G_CTLZ_ZERO_UNDEF, G_CTTZ_ZERO_UNDEF})
+//  getActionDefinitionsBuilder({G_CTLZ_ZERO_UNDEF, G_CTTZ_ZERO_UNDEF})
+//    .legalFor({{S32, S32}, {S32, S64}})
+//    .clampScalar(0, S32, S32)
+//    .clampScalar(1, S32, S64)
+//    .scalarize(0)
+//    .widenScalarToNextPow2(0, 32)
+//    .widenScalarToNextPow2(1, 32);
+
+  getActionDefinitionsBuilder(G_CTLZ_ZERO_UNDEF)
+    .legalFor({{S32, S32}, {S32, S64}})
+    .customFor({{S32, S8}, {S32, S16}})
+    .clampScalar(0, S32, S32)
+    .clampScalar(1, S32, S64)
+    .scalarize(0)
+    .widenScalarToNextPow2(0, 32)
+    .widenScalarToNextPow2(1, 32);
+//    .custom();
+
+//    .legalFor({S32})
+//    .customFor({S64})
+//    .clampScalar(0, S32, S64)
+//    .scalarize(0);
+
+  getActionDefinitionsBuilder(G_CTTZ_ZERO_UNDEF)
     .legalFor({{S32, S32}, {S32, S64}})
     .clampScalar(0, S32, S32)
     .clampScalar(1, S32, S64)
@@ -2128,6 +2151,8 @@ bool AMDGPULegalizerInfo::legalizeCustom(
   case TargetOpcode::G_CTLZ:
   case TargetOpcode::G_CTTZ:
     return legalizeCTLZ_CTTZ(MI, MRI, B);
+  case TargetOpcode::G_CTLZ_ZERO_UNDEF:
+    return legalizeCTLZ_ZERO_UNDEF(MI, MRI, B);
   case TargetOpcode::G_INTRINSIC_FPTRUNC_ROUND:
     return legalizeFPTruncRound(MI, B);
   case TargetOpcode::G_STACKSAVE:
@@ -4145,6 +4170,29 @@ bool AMDGPULegalizerInfo::legalizeCTLZ_CTTZ(MachineInstr &MI,
   return true;
 }
 
+bool AMDGPULegalizerInfo::legalizeCTLZ_ZERO_UNDEF(MachineInstr &MI,
+                                                  MachineRegisterInfo &MRI,
+                                                  MachineIRBuilder &B) const {
+  auto Dst = MI.getOperand(0).getReg();
+  auto Src = MI.getOperand(1).getReg();
+  auto DstTy = MRI.getType(Dst);
+  auto SrcTy = MRI.getType(Src);
+  auto NumBits = SrcTy.getSizeInBits();
+
+  assert(NumBits < 32u);
+
+  auto ShiftAmt = B.buildConstant(S32, 32u - NumBits);
+  Src = B.buildAnyExt(S32, {Src}).getReg(0u);
+  Src = B.buildLShr(S32, {Src}, ShiftAmt).getReg(0u);
+  B.buildInstr(AMDGPU::G_AMDGPU_FFBH_U32, {Dst}, {Src});
+  MI.eraseFromParent();
+  return true;
+
+  // LocalAccum = B.buildZExt(S32, CarryIn[0]).getReg(0);
+  // auto ShiftAmt = B.buildConstant(S32, Shift);
+  // AndMaskSrc = B.buildLShr(S32, LiveIn, ShiftAmt).getReg(0);
+}
+
 // Check that this is a G_XOR x, -1
 static bool isNot(const MachineRegisterInfo &MRI, const MachineInstr &MI) {
   if (MI.getOpcode() != TargetOpcode::G_XOR)
diff --git a/llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.h b/llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.h
index e5ba84a74a0f8..4b1d821dadc21 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.h
+++ b/llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.h
@@ -108,6 +108,8 @@ class AMDGPULegalizerInfo final : public LegalizerInfo {
   bool legalizeMul(LegalizerHelper &Helper, MachineInstr &MI) const;
   bool legalizeCTLZ_CTTZ(MachineInstr &MI, MachineRegisterInfo &MRI,
                          MachineIRBuilder &B) const;
+  bool legalizeCTLZ_ZERO_UNDEF(MachineInstr &MI, MachineRegisterInfo &MRI,
+                               MachineIRBuilder &B) const;
 
   bool loadInputValue(Register DstReg, MachineIRBuilder &B,
                       const ArgDescriptor *Arg,
diff --git a/llvm/test/CodeGen/AMDGPU/GlobalISel/legalize-ctlz-zero-undef.mir b/llvm/test/CodeGen/AMDGPU/GlobalISel/legalize-ctlz-zero-undef.mir
index fed277d7d10d0..32af5e1975a6c 100644
--- a/llvm/test/CodeGen/AMDGPU/GlobalISel/legalize-ctlz-zero-undef.mir
+++ b/llvm/test/CodeGen/AMDGPU/GlobalISel/legalize-ctlz-zero-undef.mir
@@ -81,14 +81,12 @@ body: |
     ; CHECK: liveins: $vgpr0
     ; CHECK-NEXT: {{  $}}
     ; CHECK-NEXT: [[COPY:%[0-9]+]]:_(s32) = COPY $vgpr0
-    ; CHECK-NEXT: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 65535
-    ; CHECK-NEXT: [[AND:%[0-9]+]]:_(s32) = G_AND [[COPY]], [[C]]
-    ; CHECK-NEXT: [[CTLZ_ZERO_UNDEF:%[0-9]+]]:_(s32) = G_CTLZ_ZERO_UNDEF [[AND]](s32)
-    ; CHECK-NEXT: [[C1:%[0-9]+]]:_(s32) = G_CONSTANT i32 16
-    ; CHECK-NEXT: [[SUB:%[0-9]+]]:_(s32) = G_SUB [[CTLZ_ZERO_UNDEF]], [[C1]]
-    ; CHECK-NEXT: [[COPY1:%[0-9]+]]:_(s32) = COPY [[SUB]](s32)
-    ; CHECK-NEXT: [[AND1:%[0-9]+]]:_(s32) = G_AND [[COPY1]], [[C]]
-    ; CHECK-NEXT: $vgpr0 = COPY [[AND1]](s32)
+    ; CHECK-NEXT: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 16
+    ; CHECK-NEXT: [[LSHR:%[0-9]+]]:_(s32) = G_LSHR [[COPY]], [[C]](s32)
+    ; CHECK-NEXT: [[AMDGPU_FFBH_U32:%[0-9]+]]:_(s32) = G_AMDGPU_FFBH_U32 [[LSHR]](s32)
+    ; CHECK-NEXT: [[C1:%[0-9]+]]:_(s32) = G_CONSTANT i32 65535
+    ; CHECK-NEXT: [[AND:%[0-9]+]]:_(s32) = G_AND [[AMDGPU_FFBH_U32]], [[C1]]
+    ; CHECK-NEXT: $vgpr0 = COPY [[AND]](s32)
     %0:_(s32) = COPY $vgpr0
     %1:_(s16) = G_TRUNC %0
     %2:_(s16) = G_CTLZ_ZERO_UNDEF %1
@@ -149,18 +147,15 @@ body: |
     ; CHECK-NEXT: [[BITCAST:%[0-9]+]]:_(s32) = G_BITCAST [[COPY]](<2 x s16>)
     ; CHECK-NEXT: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 16
     ; CHECK-NEXT: [[LSHR:%[0-9]+]]:_(s32) = G_LSHR [[BITCAST]], [[C]](s32)
+    ; CHECK-NEXT: [[LSHR1:%[0-9]+]]:_(s32) = G_LSHR [[BITCAST]], [[C]](s32)
+    ; CHECK-NEXT: [[AMDGPU_FFBH_U32:%[0-9]+]]:_(s32) = G_AMDGPU_FFBH_U32 [[LSHR1]](s32)
+    ; CHECK-NEXT: [[LSHR2:%[0-9]+]]:_(s32) = G_LSHR [[LSHR]], [[C]](s32)
+    ; CHECK-NEXT: [[AMDGPU_FFBH_U321:%[0-9]+]]:_(s32) = G_AMDGPU_FFBH_U32 [[LSHR2]](s32)
     ; CHECK-NEXT: [[C1:%[0-9]+]]:_(s32) = G_CONSTANT i32 65535
-    ; CHECK-NEXT: [[AND:%[0-9]+]]:_(s32) = G_AND [[BITCAST]], [[C1]]
-    ; CHECK-NEXT: [[CTLZ_ZERO_UNDEF:%[0-9]+]]:_(s32) = G_CTLZ_ZERO_UNDEF [[AND]](s32)
-    ; CHECK-NEXT: [[SUB:%[0-9]+]]:_(s32) = G_SUB [[CTLZ_ZERO_UNDEF]], [[C]]
-    ; CHECK-NEXT: [[COPY1:%[0-9]+]]:_(s32) = COPY [[SUB]](s32)
-    ; CHECK-NEXT: [[CTLZ_ZERO_UNDEF1:%[0-9]+]]:_(s32) = G_CTLZ_ZERO_UNDEF [[LSHR]](s32)
-    ; CHECK-NEXT: [[SUB1:%[0-9]+]]:_(s32) = G_SUB [[CTLZ_ZERO_UNDEF1]], [[C]]
-    ; CHECK-NEXT: [[COPY2:%[0-9]+]]:_(s32) = COPY [[SUB1]](s32)
-    ; CHECK-NEXT: [[AND1:%[0-9]+]]:_(s32) = G_AND [[COPY1]], [[C1]]
-    ; CHECK-NEXT: [[AND2:%[0-9]+]]:_(s32) = G_AND [[COPY2]], [[C1]]
-    ; CHECK-NEXT: [[SHL:%[0-9]+]]:_(s32) = G_SHL [[AND2]], [[C]](s32)
-    ; CHECK-NEXT: [[OR:%[0-9]+]]:_(s32) = G_OR [[AND1]], [[SHL]]
+    ; CHECK-NEXT: [[AND:%[0-9]+]]:_(s32) = G_AND [[AMDGPU_FFBH_U32]], [[C1]]
+    ; CHECK-NEXT: [[AND1:%[0-9]+]]:_(s32) = G_AND [[AMDGPU_FFBH_U321]], [[C1]]
+    ; CHECK-NEXT: [[SHL:%[0-9]+]]:_(s32) = G_SHL [[AND1]], [[C]](s32)
+    ; CHECK-NEXT: [[OR:%[0-9]+]]:_(s32) = G_OR [[AND]], [[SHL]]
     ; CHECK-NEXT: [[BITCAST1:%[0-9]+]]:_(<2 x s16>) = G_BITCAST [[OR]](s32)
     ; CHECK-NEXT: $vgpr0 = COPY [[BITCAST1]](<2 x s16>)
     %0:_(<2 x s16>) = COPY $vgpr0
diff --git a/llvm/test/CodeGen/AMDGPU/ctlz_zero_undef.ll b/llvm/test/CodeGen/AMDGPU/ctlz_zero_undef.ll
index 143ff5d88894b..9204eb5fdf8ca 100644
--- a/llvm/test/CodeGen/AMDGPU/ctlz_zero_undef.ll
+++ b/llvm/test/CodeGen/AMDGPU/ctlz_zero_undef.ll
@@ -377,9 +377,8 @@ define amdgpu_kernel void @s_ctlz_zero_undef_i8_with_select(ptr addrspace(1) noa
 ; GFX9-GISEL-NEXT:    s_load_dwordx2 s[2:3], s[0:1], 0x24
 ; GFX9-GISEL-NEXT:    v_mov_b32_e32 v1, 0
 ; GFX9-GISEL-NEXT:    s_waitcnt lgkmcnt(0)
-; GFX9-GISEL-NEXT:    s_and_b32 s0, s4, 0xff
+; GFX9-GISEL-NEXT:    s_lshr_b32 s0, s4, 24
 ; GFX9-GISEL-NEXT:    s_flbit_i32_b32 s0, s0
-; GFX9-GISEL-NEXT:    s_sub_i32 s0, s0, 24
 ; GFX9-GISEL-NEXT:    v_mov_b32_e32 v0, s0
 ; GFX9-GISEL-NEXT:    global_store_byte v1, v0, s[2:3]
 ; GFX9-GISEL-NEXT:    s_endpgm
@@ -453,9 +452,8 @@ define amdgpu_kernel void @s_ctlz_zero_undef_i16_with_select(ptr addrspace(1) no
 ; GFX9-GISEL-NEXT:    s_load_dwordx2 s[2:3], s[0:1], 0x24
 ; GFX9-GISEL-NEXT:    v_mov_b32_e32 v1, 0
 ; GFX9-GISEL-NEXT:    s_waitcnt lgkmcnt(0)
-; GFX9-GISEL-NEXT:    s_and_b32 s0, s4, 0xffff
+; GFX9-GISEL-NEXT:    s_lshr_b32 s0, s4, 16
 ; GFX9-GISEL-NEXT:    s_flbit_i32_b32 s0, s0
-; GFX9-GISEL-NEXT:    s_sub_i32 s0, s0, 16
 ; GFX9-GISEL-NEXT:    v_mov_b32_e32 v0, s0
 ; GFX9-GISEL-NEXT:    global_store_short v1, v0, s[2:3]
 ; GFX9-GISEL-NEXT:    s_endpgm
@@ -657,8 +655,7 @@ define amdgpu_kernel void @v_ctlz_zero_undef_i8_with_select(ptr addrspace(1) noa
 ; GFX9-GISEL-NEXT:    s_waitcnt lgkmcnt(0)
 ; GFX9-GISEL-NEXT:    global_load_ubyte v1, v0, s[2:3]
 ; GFX9-GISEL-NEXT:    s_waitcnt vmcnt(0)
-; GFX9-GISEL-NEXT:    v_ffbh_u32_e32 v2, v1
-; GFX9-GISEL-NEXT:    v_subrev_u32_e32 v2, 24, v2
+; GFX9-GISEL-NEXT:    v_ffbh_u32_sdwa v2, v1
 ; GFX9-GISEL-NEXT:    v_and_b32_e32 v2, 0xff, v2
 ; GFX9-GISEL-NEXT:    v_cmp_ne_u32_e32 vcc, 0, v1
 ; GFX9-GISEL-NEXT:    v_cndmask_b32_e32 v1, 32, v2, vcc
@@ -763,8 +760,7 @@ define amdgpu_kernel void @v_ctlz_zero_undef_i16_with_select(ptr addrspace(1) no
 ; GFX9-GISEL-NEXT:    global_load_ubyte v2, v0, s[2:3] offset:1
 ; GFX9-GISEL-NEXT:    s_waitcnt vmcnt(0)
 ; GFX9-GISEL-NEXT:    v_lshl_or_b32 v1, v2, 8, v1
-; GFX9-GISEL-NEXT:    v_ffbh_u32_e32 v2, v1
-; GFX9-GISEL-NEXT:    v_subrev_u32_e32 v2, 16, v2
+; GFX9-GISEL-NEXT:    v_ffbh_u32_sdwa v2, v1
 ; GFX9-GISEL-NEXT:    v_and_b32_e32 v2, 0xffff, v2
 ; GFX9-GISEL-NEXT:    v_cmp_ne_u32_e32 vcc, 0, v1
 ; GFX9-GISEL-NEXT:    v_cndmask_b32_e32 v1, 32, v2, vcc
@@ -1171,8 +1167,7 @@ define amdgpu_kernel void @v_ctlz_zero_undef_i8(ptr addrspace(1) noalias %out, p
 ; GFX9-GISEL-NEXT:    global_load_ubyte v0, v[0:1], off
 ; GFX9-GISEL-NEXT:    v_mov_b32_e32 v1, 0
 ; GFX9-GISEL-NEXT:    s_waitcnt vmcnt(0)
-; GFX9-GISEL-NEXT:    v_ffbh_u32_e32 v0, v0
-; GFX9-GISEL-NEXT:    v_subrev_u32_e32 v0, 24, v0
+; GFX9-GISEL-NEXT:    v_ffbh_u32_sdwa v0, v0
 ; GFX9-GISEL-NEXT:    global_store_byte v1, v0, s[0:1]
 ; GFX9-GISEL-NEXT:    s_endpgm
   %tid = call i32 @llvm.amdgcn.workitem.id.x()
@@ -1708,12 +1703,11 @@ define amdgpu_kernel void @v_ctlz_zero_undef_i8_sel_eq_neg1(ptr addrspace(1) noa
 ; GFX9-GISEL-NEXT:    v_add_co_u32_e32 v0, vcc, v1, v0
 ; GFX9-GISEL-NEXT:    v_addc_co_u32_e32 v1, vcc, v2, v3, vcc
 ; GFX9-GISEL-NEXT:    global_load_ubyte v0, v[0:1], off
-; GFX9-GISEL-NEXT:    s_waitcnt vmcnt(0)
-; GFX9-GISEL-NEXT:    v_ffbh_u32_e32 v1, v0
-; GFX9-GISEL-NEXT:    v_subrev_u32_e32 v1, 24, v1
-; GFX9-GISEL-NEXT:    v_cmp_eq_u32_e32 vcc, 0, v0
-; GFX9-GISEL-NEXT:    v_cndmask_b32_e64 v0, v1, -1, vcc
 ; GFX9-GISEL-NEXT:    v_mov_b32_e32 v1, 0
+; GFX9-GISEL-NEXT:    s_waitcnt vmcnt(0)
+; GFX9-GISEL-NEXT:    v_ffbh_u32_sdwa v2, v0
+; GFX9-GISEL-NEXT:    v_cmp_eq_u32_sdwa s[2:3], v0, v1
+; GFX9-GISEL-NEXT:    v_cndmask_b32_e64 v0, v2, -1, s[2:3]
 ; GFX9-GISEL-NEXT:    global_store_byte v1, v0, s[0:1]
 ; GFX9-GISEL-NEXT:    s_endpgm
   %tid = call i32 @llvm.amdgcn.workitem.id.x()

>From 0057bf25b4550ef3e6bcd3c943c825003d3188bb Mon Sep 17 00:00:00 2001
From: Leon Clark <leoclark at amd.com>
Date: Tue, 23 Apr 2024 00:22:45 +0100
Subject: [PATCH 04/11] Remove commented code.

---
 llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp | 18 ------------------
 1 file changed, 18 deletions(-)

diff --git a/llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp b/llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp
index c241522896084..b9f20d046e9b5 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp
@@ -1270,14 +1270,6 @@ AMDGPULegalizerInfo::AMDGPULegalizerInfo(const GCNSubtarget &ST_,
     .custom();
 
   // The 64-bit versions produce 32-bit results, but only on the SALU.
-//  getActionDefinitionsBuilder({G_CTLZ_ZERO_UNDEF, G_CTTZ_ZERO_UNDEF})
-//    .legalFor({{S32, S32}, {S32, S64}})
-//    .clampScalar(0, S32, S32)
-//    .clampScalar(1, S32, S64)
-//    .scalarize(0)
-//    .widenScalarToNextPow2(0, 32)
-//    .widenScalarToNextPow2(1, 32);
-
   getActionDefinitionsBuilder(G_CTLZ_ZERO_UNDEF)
     .legalFor({{S32, S32}, {S32, S64}})
     .customFor({{S32, S8}, {S32, S16}})
@@ -1286,12 +1278,6 @@ AMDGPULegalizerInfo::AMDGPULegalizerInfo(const GCNSubtarget &ST_,
     .scalarize(0)
     .widenScalarToNextPow2(0, 32)
     .widenScalarToNextPow2(1, 32);
-//    .custom();
-
-//    .legalFor({S32})
-//    .customFor({S64})
-//    .clampScalar(0, S32, S64)
-//    .scalarize(0);
 
   getActionDefinitionsBuilder(G_CTTZ_ZERO_UNDEF)
     .legalFor({{S32, S32}, {S32, S64}})
@@ -4187,10 +4173,6 @@ bool AMDGPULegalizerInfo::legalizeCTLZ_ZERO_UNDEF(MachineInstr &MI,
   B.buildInstr(AMDGPU::G_AMDGPU_FFBH_U32, {Dst}, {Src});
   MI.eraseFromParent();
   return true;
-
-  // LocalAccum = B.buildZExt(S32, CarryIn[0]).getReg(0);
-  // auto ShiftAmt = B.buildConstant(S32, Shift);
-  // AndMaskSrc = B.buildLShr(S32, LiveIn, ShiftAmt).getReg(0);
 }
 
 // Check that this is a G_XOR x, -1

>From 8b67341b0e36ace47fb23819bd823791aa6fb248 Mon Sep 17 00:00:00 2001
From: Leon Clark <leoclark at amd.com>
Date: Tue, 23 Apr 2024 00:43:07 +0100
Subject: [PATCH 05/11] Clang formatting.

---
 .../lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp | 26 +++++++++----------
 1 file changed, 13 insertions(+), 13 deletions(-)

diff --git a/llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp b/llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp
index b9f20d046e9b5..20e5e42ca1f9a 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp
@@ -1271,21 +1271,21 @@ AMDGPULegalizerInfo::AMDGPULegalizerInfo(const GCNSubtarget &ST_,
 
   // The 64-bit versions produce 32-bit results, but only on the SALU.
   getActionDefinitionsBuilder(G_CTLZ_ZERO_UNDEF)
-    .legalFor({{S32, S32}, {S32, S64}})
-    .customFor({{S32, S8}, {S32, S16}})
-    .clampScalar(0, S32, S32)
-    .clampScalar(1, S32, S64)
-    .scalarize(0)
-    .widenScalarToNextPow2(0, 32)
-    .widenScalarToNextPow2(1, 32);
+      .legalFor({{S32, S32}, {S32, S64}})
+      .customFor({{S32, S8}, {S32, S16}})
+      .clampScalar(0, S32, S32)
+      .clampScalar(1, S32, S64)
+      .scalarize(0)
+      .widenScalarToNextPow2(0, 32)
+      .widenScalarToNextPow2(1, 32);
 
   getActionDefinitionsBuilder(G_CTTZ_ZERO_UNDEF)
-    .legalFor({{S32, S32}, {S32, S64}})
-    .clampScalar(0, S32, S32)
-    .clampScalar(1, S32, S64)
-    .scalarize(0)
-    .widenScalarToNextPow2(0, 32)
-    .widenScalarToNextPow2(1, 32);
+      .legalFor({{S32, S32}, {S32, S64}})
+      .clampScalar(0, S32, S32)
+      .clampScalar(1, S32, S64)
+      .scalarize(0)
+      .widenScalarToNextPow2(0, 32)
+      .widenScalarToNextPow2(1, 32);
 
   // S64 is only legal on SALU, and needs to be broken into 32-bit elements in
   // RegBankSelect.

>From 381dc78286de49f57fbcd6caac7cc2d84387e558 Mon Sep 17 00:00:00 2001
From: Leon Clark <leoclark at amd.com>
Date: Tue, 23 Apr 2024 12:09:12 +0100
Subject: [PATCH 06/11] Address review comments.

---
 llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp b/llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp
index 20e5e42ca1f9a..6e79d717810e9 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp
@@ -4159,18 +4159,18 @@ bool AMDGPULegalizerInfo::legalizeCTLZ_CTTZ(MachineInstr &MI,
 bool AMDGPULegalizerInfo::legalizeCTLZ_ZERO_UNDEF(MachineInstr &MI,
                                                   MachineRegisterInfo &MRI,
                                                   MachineIRBuilder &B) const {
-  auto Dst = MI.getOperand(0).getReg();
-  auto Src = MI.getOperand(1).getReg();
-  auto DstTy = MRI.getType(Dst);
-  auto SrcTy = MRI.getType(Src);
-  auto NumBits = SrcTy.getSizeInBits();
+  Register Dst = MI.getOperand(0).getReg();
+  Register Src = MI.getOperand(1).getReg();
+  LLT DstTy = MRI.getType(Dst);
+  LLT SrcTy = MRI.getType(Src);
+  TypeSize NumBits = SrcTy.getSizeInBits();
 
   assert(NumBits < 32u);
 
   auto ShiftAmt = B.buildConstant(S32, 32u - NumBits);
-  Src = B.buildAnyExt(S32, {Src}).getReg(0u);
-  Src = B.buildLShr(S32, {Src}, ShiftAmt).getReg(0u);
-  B.buildInstr(AMDGPU::G_AMDGPU_FFBH_U32, {Dst}, {Src});
+  auto Tmp = B.buildAnyExt(S32, {Src}).getReg(0u);
+  Tmp = B.buildLShr(S32, {Tmp}, ShiftAmt).getReg(0u);
+  B.buildInstr(AMDGPU::G_AMDGPU_FFBH_U32, {Dst}, {Tmp});
   MI.eraseFromParent();
   return true;
 }

>From b19d9e290198bec78a9d6303b6e819b51ade4dec Mon Sep 17 00:00:00 2001
From: Leon Clark <leoclark at amd.com>
Date: Thu, 2 May 2024 22:24:12 +0100
Subject: [PATCH 07/11] Address review comments.

---
 llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp  | 6 +++---
 llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp | 7 +++----
 2 files changed, 6 insertions(+), 7 deletions(-)

diff --git a/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp b/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp
index d01d0483af071..980e58510ceb7 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp
@@ -3127,9 +3127,9 @@ SDValue AMDGPUTargetLowering::lowerCTLZResults(SDValue Op,
   assert(isCtlzOpc(Opc));
   assert(ResultVT == Arg.getValueType());
 
-  auto const NumBits = ResultVT.getFixedSizeInBits();
-  auto NumExtBits = DAG.getConstant(32u - NumBits, SL, MVT::i32);
-  auto NewOp = SDValue();
+  const uint64_t NumBits = ResultVT.getFixedSizeInBits();
+  SDValue NumExtBits = DAG.getConstant(32u - NumBits, SL, MVT::i32);
+  SDValue NewOp;
 
   if (Opc == ISD::CTLZ_ZERO_UNDEF) {
     NewOp = DAG.getNode(ISD::ANY_EXTEND, SL, MVT::i32, Arg);
diff --git a/llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp b/llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp
index 6e79d717810e9..241bdd743d7e5 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp
@@ -4161,16 +4161,15 @@ bool AMDGPULegalizerInfo::legalizeCTLZ_ZERO_UNDEF(MachineInstr &MI,
                                                   MachineIRBuilder &B) const {
   Register Dst = MI.getOperand(0).getReg();
   Register Src = MI.getOperand(1).getReg();
-  LLT DstTy = MRI.getType(Dst);
   LLT SrcTy = MRI.getType(Src);
   TypeSize NumBits = SrcTy.getSizeInBits();
 
   assert(NumBits < 32u);
 
   auto ShiftAmt = B.buildConstant(S32, 32u - NumBits);
-  auto Tmp = B.buildAnyExt(S32, {Src}).getReg(0u);
-  Tmp = B.buildLShr(S32, {Tmp}, ShiftAmt).getReg(0u);
-  B.buildInstr(AMDGPU::G_AMDGPU_FFBH_U32, {Dst}, {Tmp});
+  auto Extend = B.buildAnyExt(S32, {Src}).getReg(0u);
+  auto Shift = B.buildLShr(S32, {Extend}, ShiftAmt).getReg(0u);
+  B.buildInstr(AMDGPU::G_AMDGPU_FFBH_U32, {Dst}, {Shift});
   MI.eraseFromParent();
   return true;
 }

>From 375226a2ef32ac5a4938df4cef6914f8e6000137 Mon Sep 17 00:00:00 2001
From: Leon Clark <leoclark at amd.com>
Date: Wed, 8 May 2024 11:57:25 +0100
Subject: [PATCH 08/11] Address comments.

---
 llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp b/llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp
index 241bdd743d7e5..ddd91bef10cda 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp
@@ -1272,7 +1272,7 @@ AMDGPULegalizerInfo::AMDGPULegalizerInfo(const GCNSubtarget &ST_,
   // The 64-bit versions produce 32-bit results, but only on the SALU.
   getActionDefinitionsBuilder(G_CTLZ_ZERO_UNDEF)
       .legalFor({{S32, S32}, {S32, S64}})
-      .customFor({{S32, S8}, {S32, S16}})
+      .customIf(scalarNarrowerThan(0, 32))
       .clampScalar(0, S32, S32)
       .clampScalar(1, S32, S64)
       .scalarize(0)
@@ -4168,7 +4168,7 @@ bool AMDGPULegalizerInfo::legalizeCTLZ_ZERO_UNDEF(MachineInstr &MI,
 
   auto ShiftAmt = B.buildConstant(S32, 32u - NumBits);
   auto Extend = B.buildAnyExt(S32, {Src}).getReg(0u);
-  auto Shift = B.buildLShr(S32, {Extend}, ShiftAmt).getReg(0u);
+  auto Shift = B.buildLShr(S32, {Extend}, ShiftAmt);
   B.buildInstr(AMDGPU::G_AMDGPU_FFBH_U32, {Dst}, {Shift});
   MI.eraseFromParent();
   return true;

>From f9afbe93e75142c67e8f38b5692dd074efff4e6d Mon Sep 17 00:00:00 2001
From: Leon Clark <leoclark at amd.com>
Date: Thu, 9 May 2024 16:00:20 +0100
Subject: [PATCH 09/11] Address review comments.

---
 llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp     |  5 +++--
 .../AMDGPU/GlobalISel/legalize-ctlz-zero-undef.mir | 14 ++++++--------
 2 files changed, 9 insertions(+), 10 deletions(-)

diff --git a/llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp b/llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp
index ddd91bef10cda..15a4b6796880f 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp
@@ -1272,7 +1272,7 @@ AMDGPULegalizerInfo::AMDGPULegalizerInfo(const GCNSubtarget &ST_,
   // The 64-bit versions produce 32-bit results, but only on the SALU.
   getActionDefinitionsBuilder(G_CTLZ_ZERO_UNDEF)
       .legalFor({{S32, S32}, {S32, S64}})
-      .customIf(scalarNarrowerThan(0, 32))
+      .customIf(scalarNarrowerThan(1, 32))
       .clampScalar(0, S32, S32)
       .clampScalar(1, S32, S64)
       .scalarize(0)
@@ -4169,7 +4169,8 @@ bool AMDGPULegalizerInfo::legalizeCTLZ_ZERO_UNDEF(MachineInstr &MI,
   auto ShiftAmt = B.buildConstant(S32, 32u - NumBits);
   auto Extend = B.buildAnyExt(S32, {Src}).getReg(0u);
   auto Shift = B.buildLShr(S32, {Extend}, ShiftAmt);
-  B.buildInstr(AMDGPU::G_AMDGPU_FFBH_U32, {Dst}, {Shift});
+  auto Ctlz = B.buildInstr(AMDGPU::G_AMDGPU_FFBH_U32, {S32}, {Shift});
+  B.buildTrunc(Dst, Ctlz);
   MI.eraseFromParent();
   return true;
 }
diff --git a/llvm/test/CodeGen/AMDGPU/GlobalISel/legalize-ctlz-zero-undef.mir b/llvm/test/CodeGen/AMDGPU/GlobalISel/legalize-ctlz-zero-undef.mir
index 32af5e1975a6c..7748b481cf5b7 100644
--- a/llvm/test/CodeGen/AMDGPU/GlobalISel/legalize-ctlz-zero-undef.mir
+++ b/llvm/test/CodeGen/AMDGPU/GlobalISel/legalize-ctlz-zero-undef.mir
@@ -174,14 +174,12 @@ body: |
     ; CHECK: liveins: $vgpr0
     ; CHECK-NEXT: {{  $}}
     ; CHECK-NEXT: [[COPY:%[0-9]+]]:_(s32) = COPY $vgpr0
-    ; CHECK-NEXT: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 127
-    ; CHECK-NEXT: [[AND:%[0-9]+]]:_(s32) = G_AND [[COPY]], [[C]]
-    ; CHECK-NEXT: [[CTLZ_ZERO_UNDEF:%[0-9]+]]:_(s32) = G_CTLZ_ZERO_UNDEF [[AND]](s32)
-    ; CHECK-NEXT: [[C1:%[0-9]+]]:_(s32) = G_CONSTANT i32 25
-    ; CHECK-NEXT: [[SUB:%[0-9]+]]:_(s32) = G_SUB [[CTLZ_ZERO_UNDEF]], [[C1]]
-    ; CHECK-NEXT: [[COPY1:%[0-9]+]]:_(s32) = COPY [[SUB]](s32)
-    ; CHECK-NEXT: [[AND1:%[0-9]+]]:_(s32) = G_AND [[COPY1]], [[C]]
-    ; CHECK-NEXT: $vgpr0 = COPY [[AND1]](s32)
+    ; CHECK-NEXT: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 25
+    ; CHECK-NEXT: [[LSHR:%[0-9]+]]:_(s32) = G_LSHR [[COPY]], [[C]](s32)
+    ; CHECK-NEXT: [[FFBH:%[0-9]+]]:_(s32) = G_AMDGPU_FFBH_U32 [[LSHR]](s32)
+    ; CHECK-NEXT: [[C1:%[0-9]+]]:_(s32) = G_CONSTANT i32 127
+    ; CHECK-NEXT: [[AND:%[0-9]+]]:_(s32) = G_AND [[FFBH]], [[C1]]
+    ; CHECK-NEXT: $vgpr0 = COPY [[AND]](s32)
     %0:_(s32) = COPY $vgpr0
     %1:_(s7) = G_TRUNC %0
     %2:_(s7) = G_CTLZ_ZERO_UNDEF %1

>From 1b08b1446a19ad3690ae95b987bdf123c067e446 Mon Sep 17 00:00:00 2001
From: Leon Clark <leoclark at amd.com>
Date: Fri, 10 May 2024 14:47:22 +0100
Subject: [PATCH 10/11] Address review comments.

---
 llvm/test/CodeGen/AMDGPU/ctlz_zero_undef.ll | 217 ++++++++------------
 1 file changed, 90 insertions(+), 127 deletions(-)

diff --git a/llvm/test/CodeGen/AMDGPU/ctlz_zero_undef.ll b/llvm/test/CodeGen/AMDGPU/ctlz_zero_undef.ll
index 9204eb5fdf8ca..b6e53c9e55174 100644
--- a/llvm/test/CodeGen/AMDGPU/ctlz_zero_undef.ll
+++ b/llvm/test/CodeGen/AMDGPU/ctlz_zero_undef.ll
@@ -2186,10 +2186,9 @@ define i7 @v_ctlz_zero_undef_i7(i7 %val) {
 ; GFX9-GISEL-LABEL: v_ctlz_zero_undef_i7:
 ; GFX9-GISEL:       ; %bb.0:
 ; GFX9-GISEL-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
-; GFX9-GISEL-NEXT:    v_and_b32_e32 v0, 0x7f, v0
-; GFX9-GISEL-NEXT:    v_ffbh_u32_e32 v0, v0
-; GFX9-GISEL-NEXT:    v_subrev_u32_e32 v0, 25, v0
-; GFX9-GISEL-NEXT:    s_setpc_b64 s[30:31]
+; GFX9-GISEL-NEXT:    v_lshrrev_b32_e32 v0, 25, v0
+; GFX9-GISEL-NEXT:  	v_ffbh_u32_e32 v0, v0
+; GFX9-GISEL-NEXT:  	s_setpc_b64 s[30:31]
   %ctlz = call i7 @llvm.ctlz.i7(i7 %val, i1 true)
   ret i7 %ctlz
 }
@@ -2276,19 +2275,18 @@ define amdgpu_kernel void @s_ctlz_zero_undef_i18(ptr addrspace(1) noalias %out,
 ; GFX9-GISEL-LABEL: s_ctlz_zero_undef_i18:
 ; GFX9-GISEL:       ; %bb.0:
 ; GFX9-GISEL-NEXT:    s_load_dword s4, s[0:1], 0x2c
-; GFX9-GISEL-NEXT:    s_load_dwordx2 s[2:3], s[0:1], 0x24
-; GFX9-GISEL-NEXT:    v_mov_b32_e32 v0, 0
-; GFX9-GISEL-NEXT:    s_waitcnt lgkmcnt(0)
-; GFX9-GISEL-NEXT:    s_and_b32 s0, s4, 0x3ffff
-; GFX9-GISEL-NEXT:    s_flbit_i32_b32 s0, s0
-; GFX9-GISEL-NEXT:    s_sub_i32 s0, s0, 14
-; GFX9-GISEL-NEXT:    s_and_b32 s0, s0, 0x3ffff
-; GFX9-GISEL-NEXT:    s_lshr_b32 s1, s0, 16
-; GFX9-GISEL-NEXT:    v_mov_b32_e32 v1, s0
-; GFX9-GISEL-NEXT:    global_store_short v0, v1, s[2:3]
-; GFX9-GISEL-NEXT:    v_mov_b32_e32 v1, s1
-; GFX9-GISEL-NEXT:    global_store_byte v0, v1, s[2:3] offset:2
-; GFX9-GISEL-NEXT:    s_endpgm
+; GFX9-GISEL-NEXT:  	s_load_dwordx2 s[2:3], s[0:1], 0x24
+; GFX9-GISEL-NEXT:  	v_mov_b32_e32 v0, 0
+; GFX9-GISEL-NEXT:  	s_waitcnt lgkmcnt(0)
+; GFX9-GISEL-NEXT:  	s_lshr_b32 s0, s4, 14
+; GFX9-GISEL-NEXT:  	s_flbit_i32_b32 s0, s0
+; GFX9-GISEL-NEXT:  	s_and_b32 s0, s0, 0x3ffff
+; GFX9-GISEL-NEXT:  	s_lshr_b32 s1, s0, 16
+; GFX9-GISEL-NEXT:  	v_mov_b32_e32 v1, s0
+; GFX9-GISEL-NEXT:  	global_store_short v0, v1, s[2:3]
+; GFX9-GISEL-NEXT:  	v_mov_b32_e32 v1, s1
+; GFX9-GISEL-NEXT:  	global_store_byte v0, v1, s[2:3] offset:2
+; GFX9-GISEL-NEXT:  	s_endpgm
   %ctlz = call i18 @llvm.ctlz.i18(i18 %val, i1 true) nounwind readnone
   store i18 %ctlz, ptr addrspace(1) %out, align 4
   ret void
@@ -2319,10 +2317,9 @@ define i18 @v_ctlz_zero_undef_i18(i18 %val) {
 ; GFX9-GISEL-LABEL: v_ctlz_zero_undef_i18:
 ; GFX9-GISEL:       ; %bb.0:
 ; GFX9-GISEL-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
-; GFX9-GISEL-NEXT:    v_and_b32_e32 v0, 0x3ffff, v0
-; GFX9-GISEL-NEXT:    v_ffbh_u32_e32 v0, v0
-; GFX9-GISEL-NEXT:    v_subrev_u32_e32 v0, 14, v0
-; GFX9-GISEL-NEXT:    s_setpc_b64 s[30:31]
+; GFX9-GISEL-NEXT:    v_lshrrev_b32_e32 v0, 14, v0
+; GFX9-GISEL-NEXT:  	v_ffbh_u32_e32 v0, v0
+; GFX9-GISEL-NEXT:  	s_setpc_b64 s[30:31]
   %ctlz = call i18 @llvm.ctlz.i18(i18 %val, i1 true)
   ret i18 %ctlz
 }
@@ -2358,13 +2355,11 @@ define <2 x i18> @v_ctlz_zero_undef_v2i18(<2 x i18> %val) {
 ; GFX9-GISEL-LABEL: v_ctlz_zero_undef_v2i18:
 ; GFX9-GISEL:       ; %bb.0:
 ; GFX9-GISEL-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
-; GFX9-GISEL-NEXT:    v_and_b32_e32 v0, 0x3ffff, v0
-; GFX9-GISEL-NEXT:    v_and_b32_e32 v1, 0x3ffff, v1
-; GFX9-GISEL-NEXT:    v_ffbh_u32_e32 v0, v0
-; GFX9-GISEL-NEXT:    v_ffbh_u32_e32 v1, v1
-; GFX9-GISEL-NEXT:    v_subrev_u32_e32 v0, 14, v0
-; GFX9-GISEL-NEXT:    v_subrev_u32_e32 v1, 14, v1
-; GFX9-GISEL-NEXT:    s_setpc_b64 s[30:31]
+; GFX9-GISEL-NEXT:    v_lshrrev_b32_e32 v0, 14, v0
+; GFX9-GISEL-NEXT:  	v_lshrrev_b32_e32 v1, 14, v1
+; GFX9-GISEL-NEXT:  	v_ffbh_u32_e32 v0, v0
+; GFX9-GISEL-NEXT:  	v_ffbh_u32_e32 v1, v1
+; GFX9-GISEL-NEXT:  	s_setpc_b64 s[30:31]
   %ctlz = call <2 x i18> @llvm.ctlz.v2i18(<2 x i18> %val, i1 true)
   ret <2 x i18> %ctlz
 }
@@ -2373,17 +2368,13 @@ define <2 x i16> @v_ctlz_zero_undef_v2i16(<2 x i16> %val) {
 ; SI-LABEL: v_ctlz_zero_undef_v2i16:
 ; SI:       ; %bb.0:
 ; SI-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
-; SI-NEXT:    v_and_b32_e32 v1, 0xffff, v1
-; SI-NEXT:    v_and_b32_e32 v0, 0xffff, v0
-; SI-NEXT:    v_ffbh_u32_e32 v1, v1
-; SI-NEXT:    v_ffbh_u32_e32 v0, v0
-; SI-NEXT:    v_add_i32_e32 v1, vcc, -16, v1
-; SI-NEXT:    v_add_i32_e32 v0, vcc, -16, v0
-; SI-NEXT:    v_lshlrev_b32_e32 v2, 16, v1
-; SI-NEXT:    v_and_b32_e32 v0, 0xffff, v0
-; SI-NEXT:    v_or_b32_e32 v0, v0, v2
-; SI-NEXT:    v_and_b32_e32 v1, 0xffff, v1
-; SI-NEXT:    s_setpc_b64 s[30:31]
+; SI-NEXT:    v_lshlrev_b32_e32 v1, 16, v1
+; SI-NEXT:  	v_lshlrev_b32_e32 v0, 16, v0
+; SI-NEXT:  	v_ffbh_u32_e32 v1, v1
+; SI-NEXT:  	v_lshlrev_b32_e32 v2, 16, v1
+; SI-NEXT:  	v_ffbh_u32_e32 v0, v0
+; SI-NEXT:  	v_or_b32_e32 v0, v0, v2
+; SI-NEXT:  	s_setpc_b64 s[30:31]
 ;
 ; VI-LABEL: v_ctlz_zero_undef_v2i16:
 ; VI:       ; %bb.0:
@@ -2403,13 +2394,11 @@ define <2 x i16> @v_ctlz_zero_undef_v2i16(<2 x i16> %val) {
 ; GFX9-GISEL-LABEL: v_ctlz_zero_undef_v2i16:
 ; GFX9-GISEL:       ; %bb.0:
 ; GFX9-GISEL-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
-; GFX9-GISEL-NEXT:    v_ffbh_u32_sdwa v1, v0 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:WORD_0
-; GFX9-GISEL-NEXT:    v_subrev_u32_e32 v1, 16, v1
 ; GFX9-GISEL-NEXT:    v_ffbh_u32_sdwa v0, v0 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:WORD_1
-; GFX9-GISEL-NEXT:    v_subrev_u32_e32 v0, 16, v0
-; GFX9-GISEL-NEXT:    v_and_b32_e32 v1, 0xffff, v1
-; GFX9-GISEL-NEXT:    v_lshl_or_b32 v0, v0, 16, v1
-; GFX9-GISEL-NEXT:    s_setpc_b64 s[30:31]
+; GFX9-GISEL-NEXT:  	s_flbit_i32_b32 s4, 0
+; GFX9-GISEL-NEXT:  	v_and_b32_e32 v0, 0xffff, v0
+; GFX9-GISEL-NEXT:  	v_lshl_or_b32 v0, s4, 16, v0
+; GFX9-GISEL-NEXT:  	s_setpc_b64 s[30:31]
   %ctlz = call <2 x i16> @llvm.ctlz.v2i16(<2 x i16> %val, i1 true)
   ret <2 x i16> %ctlz
 }
@@ -2418,22 +2407,17 @@ define <3 x i16> @v_ctlz_zero_undef_v3i16(<3 x i16> %val) {
 ; SI-LABEL: v_ctlz_zero_undef_v3i16:
 ; SI:       ; %bb.0:
 ; SI-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
-; SI-NEXT:    v_and_b32_e32 v1, 0xffff, v1
-; SI-NEXT:    v_and_b32_e32 v0, 0xffff, v0
-; SI-NEXT:    v_and_b32_e32 v2, 0xffff, v2
-; SI-NEXT:    v_ffbh_u32_e32 v1, v1
-; SI-NEXT:    v_ffbh_u32_e32 v0, v0
-; SI-NEXT:    v_ffbh_u32_e32 v2, v2
 ; SI-NEXT:    v_lshlrev_b32_e32 v1, 16, v1
-; SI-NEXT:    v_add_i32_e32 v0, vcc, -16, v0
-; SI-NEXT:    v_add_i32_e32 v3, vcc, -16, v2
-; SI-NEXT:    v_and_b32_e32 v0, 0xffff, v0
-; SI-NEXT:    v_and_b32_e32 v2, 0xffff, v3
-; SI-NEXT:    v_or_b32_e32 v0, v1, v0
-; SI-NEXT:    v_add_i32_e32 v0, vcc, 0xfff00000, v0
-; SI-NEXT:    v_or_b32_e32 v2, 0x100000, v2
-; SI-NEXT:    v_alignbit_b32 v1, v3, v0, 16
-; SI-NEXT:    s_setpc_b64 s[30:31]
+; SI-NEXT:  	v_lshlrev_b32_e32 v0, 16, v0
+; SI-NEXT:  	v_lshlrev_b32_e32 v2, 16, v2
+; SI-NEXT:  	v_ffbh_u32_e32 v1, v1
+; SI-NEXT:  	v_ffbh_u32_e32 v0, v0
+; SI-NEXT:  	v_ffbh_u32_e32 v3, v2
+; SI-NEXT:  	v_lshlrev_b32_e32 v1, 16, v1
+; SI-NEXT:  	v_or_b32_e32 v0, v0, v1
+; SI-NEXT:  	v_or_b32_e32 v2, 0x200000, v3
+; SI-NEXT:  	v_alignbit_b32 v1, v3, v0, 16
+; SI-NEXT:  	s_setpc_b64 s[30:31]
 ;
 ; VI-LABEL: v_ctlz_zero_undef_v3i16:
 ; VI:       ; %bb.0:
@@ -2455,15 +2439,12 @@ define <3 x i16> @v_ctlz_zero_undef_v3i16(<3 x i16> %val) {
 ; GFX9-GISEL-LABEL: v_ctlz_zero_undef_v3i16:
 ; GFX9-GISEL:       ; %bb.0:
 ; GFX9-GISEL-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
-; GFX9-GISEL-NEXT:    v_ffbh_u32_sdwa v2, v0 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:WORD_0
-; GFX9-GISEL-NEXT:    v_subrev_u32_e32 v2, 16, v2
 ; GFX9-GISEL-NEXT:    v_ffbh_u32_sdwa v0, v0 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:WORD_1
-; GFX9-GISEL-NEXT:    v_subrev_u32_e32 v0, 16, v0
-; GFX9-GISEL-NEXT:    v_ffbh_u32_sdwa v1, v1 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:WORD_0
-; GFX9-GISEL-NEXT:    v_and_b32_e32 v2, 0xffff, v2
-; GFX9-GISEL-NEXT:    v_subrev_u32_e32 v1, 16, v1
-; GFX9-GISEL-NEXT:    v_lshl_or_b32 v0, v0, 16, v2
-; GFX9-GISEL-NEXT:    s_setpc_b64 s[30:31]
+; GFX9-GISEL-NEXT:  	s_flbit_i32_b32 s4, 0
+; GFX9-GISEL-NEXT:  	v_and_b32_e32 v0, 0xffff, v0
+; GFX9-GISEL-NEXT:  	v_ffbh_u32_sdwa v1, v1 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:WORD_1
+; GFX9-GISEL-NEXT:  	v_lshl_or_b32 v0, s4, 16, v0
+; GFX9-GISEL-NEXT:  	s_setpc_b64 s[30:31]
   %ctlz = call <3 x i16> @llvm.ctlz.v3i16(<3 x i16> %val, i1 true)
   ret <3 x i16> %ctlz
 }
@@ -2472,27 +2453,21 @@ define <4 x i16> @v_ctlz_zero_undef_v4i16(<4 x i16> %val) {
 ; SI-LABEL: v_ctlz_zero_undef_v4i16:
 ; SI:       ; %bb.0:
 ; SI-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
-; SI-NEXT:    v_and_b32_e32 v3, 0xffff, v3
-; SI-NEXT:    v_and_b32_e32 v2, 0xffff, v2
-; SI-NEXT:    v_and_b32_e32 v1, 0xffff, v1
-; SI-NEXT:    v_and_b32_e32 v0, 0xffff, v0
-; SI-NEXT:    v_ffbh_u32_e32 v3, v3
-; SI-NEXT:    v_ffbh_u32_e32 v2, v2
-; SI-NEXT:    v_ffbh_u32_e32 v1, v1
-; SI-NEXT:    v_ffbh_u32_e32 v0, v0
 ; SI-NEXT:    v_lshlrev_b32_e32 v3, 16, v3
-; SI-NEXT:    v_add_i32_e32 v2, vcc, -16, v2
-; SI-NEXT:    v_lshlrev_b32_e32 v1, 16, v1
-; SI-NEXT:    v_add_i32_e32 v0, vcc, -16, v0
-; SI-NEXT:    v_and_b32_e32 v2, 0xffff, v2
-; SI-NEXT:    v_and_b32_e32 v0, 0xffff, v0
-; SI-NEXT:    v_or_b32_e32 v2, v3, v2
-; SI-NEXT:    v_or_b32_e32 v0, v1, v0
-; SI-NEXT:    v_add_i32_e32 v2, vcc, 0xfff00000, v2
-; SI-NEXT:    v_add_i32_e32 v0, vcc, 0xfff00000, v0
-; SI-NEXT:    v_alignbit_b32 v1, v2, v0, 16
-; SI-NEXT:    v_lshrrev_b32_e32 v3, 16, v2
-; SI-NEXT:    s_setpc_b64 s[30:31]
+; SI-NEXT:  	v_lshlrev_b32_e32 v2, 16, v2
+; SI-NEXT:  	v_lshlrev_b32_e32 v1, 16, v1
+; SI-NEXT:  	v_lshlrev_b32_e32 v0, 16, v0
+; SI-NEXT:  	v_ffbh_u32_e32 v3, v3
+; SI-NEXT:  	v_ffbh_u32_e32 v2, v2
+; SI-NEXT:  	v_ffbh_u32_e32 v1, v1
+; SI-NEXT:  	v_ffbh_u32_e32 v0, v0
+; SI-NEXT:  	v_lshlrev_b32_e32 v3, 16, v3
+; SI-NEXT:  	v_lshlrev_b32_e32 v1, 16, v1
+; SI-NEXT:  	v_or_b32_e32 v2, v2, v3
+; SI-NEXT:  	v_or_b32_e32 v0, v0, v1
+; SI-NEXT:  	v_alignbit_b32 v1, v2, v0, 16
+; SI-NEXT:  	v_lshrrev_b32_e32 v3, 16, v2
+; SI-NEXT:  	s_setpc_b64 s[30:31]
 ;
 ; VI-LABEL: v_ctlz_zero_undef_v4i16:
 ; VI:       ; %bb.0:
@@ -2517,19 +2492,14 @@ define <4 x i16> @v_ctlz_zero_undef_v4i16(<4 x i16> %val) {
 ; GFX9-GISEL-LABEL: v_ctlz_zero_undef_v4i16:
 ; GFX9-GISEL:       ; %bb.0:
 ; GFX9-GISEL-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
-; GFX9-GISEL-NEXT:    v_ffbh_u32_sdwa v2, v0 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:WORD_0
-; GFX9-GISEL-NEXT:    v_subrev_u32_e32 v2, 16, v2
 ; GFX9-GISEL-NEXT:    v_ffbh_u32_sdwa v0, v0 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:WORD_1
-; GFX9-GISEL-NEXT:    v_ffbh_u32_sdwa v3, v1 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:WORD_0
-; GFX9-GISEL-NEXT:    v_subrev_u32_e32 v0, 16, v0
-; GFX9-GISEL-NEXT:    v_subrev_u32_e32 v3, 16, v3
-; GFX9-GISEL-NEXT:    v_ffbh_u32_sdwa v1, v1 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:WORD_1
-; GFX9-GISEL-NEXT:    v_and_b32_e32 v2, 0xffff, v2
-; GFX9-GISEL-NEXT:    v_subrev_u32_e32 v1, 16, v1
-; GFX9-GISEL-NEXT:    v_lshl_or_b32 v0, v0, 16, v2
-; GFX9-GISEL-NEXT:    v_and_b32_e32 v2, 0xffff, v3
-; GFX9-GISEL-NEXT:    v_lshl_or_b32 v1, v1, 16, v2
-; GFX9-GISEL-NEXT:    s_setpc_b64 s[30:31]
+; GFX9-GISEL-NEXT:  	v_ffbh_u32_sdwa v1, v1 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:WORD_1
+; GFX9-GISEL-NEXT:  	s_flbit_i32_b32 s4, 0
+; GFX9-GISEL-NEXT:  	v_and_b32_e32 v0, 0xffff, v0
+; GFX9-GISEL-NEXT:  	v_and_b32_e32 v1, 0xffff, v1
+; GFX9-GISEL-NEXT:  	v_lshl_or_b32 v0, s4, 16, v0
+; GFX9-GISEL-NEXT:  	v_lshl_or_b32 v1, s4, 16, v1
+; GFX9-GISEL-NEXT:  	s_setpc_b64 s[30:31]
   %ctlz = call <4 x i16> @llvm.ctlz.v4i16(<4 x i16> %val, i1 true)
   ret <4 x i16> %ctlz
 }
@@ -2538,28 +2508,25 @@ define <2 x i8> @v_ctlz_zero_undef_v2i8(<2 x i8> %val) {
 ; SI-LABEL: v_ctlz_zero_undef_v2i8:
 ; SI:       ; %bb.0:
 ; SI-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
-; SI-NEXT:    v_and_b32_e32 v1, 0xff, v1
-; SI-NEXT:    v_and_b32_e32 v0, 0xff, v0
+; SI-NEXT:    v_lshlrev_b32_e32 v1, 24, v1
+; SI-NEXT:    v_lshlrev_b32_e32 v0, 24, v0
 ; SI-NEXT:    v_ffbh_u32_e32 v1, v1
+; SI-NEXT:    v_lshlrev_b32_e32 v2, 8, v1
 ; SI-NEXT:    v_ffbh_u32_e32 v0, v0
-; SI-NEXT:    v_lshlrev_b32_e32 v1, 8, v1
-; SI-NEXT:    v_subrev_i32_e32 v0, vcc, 24, v0
-; SI-NEXT:    v_and_b32_e32 v0, 0xff, v0
-; SI-NEXT:    v_or_b32_e32 v0, v1, v0
-; SI-NEXT:    v_add_i32_e32 v0, vcc, 0xffffe800, v0
-; SI-NEXT:    v_bfe_u32 v1, v0, 8, 8
+; SI-NEXT:    v_or_b32_e32 v0, v0, v2
 ; SI-NEXT:    s_setpc_b64 s[30:31]
 ;
 ; VI-LABEL: v_ctlz_zero_undef_v2i8:
 ; VI:       ; %bb.0:
 ; VI-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
-; VI-NEXT:    v_ffbh_u32_sdwa v1, v1 dst_sel:BYTE_1 dst_unused:UNUSED_PAD src0_sel:BYTE_0
-; VI-NEXT:    v_ffbh_u32_sdwa v0, v0 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:BYTE_0
-; VI-NEXT:    v_add_u16_e32 v1, 0xe800, v1
-; VI-NEXT:    v_subrev_u16_e32 v0, 24, v0
-; VI-NEXT:    v_or_b32_sdwa v0, v0, v1 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:BYTE_0 src1_sel:DWORD
-; VI-NEXT:    v_lshrrev_b16_e32 v1, 8, v1
-; VI-NEXT:    s_setpc_b64 s[30:31]
+; VI-NEXT:    v_lshlrev_b32_e32 v1, 24, v1
+; VI-NEXT:  	v_ffbh_u32_e32 v1, v1
+; VI-NEXT:  	v_lshlrev_b32_e32 v0, 24, v0
+; VI-NEXT:  	v_lshlrev_b16_e32 v2, 8, v1
+; VI-NEXT:  	v_ffbh_u32_e32 v0, v0
+; VI-NEXT:  	v_or_b32_e32 v0, v0, v2
+; VI-NEXT:  	v_and_b32_e32 v1, 0xff, v1
+; VI-NEXT:  	s_setpc_b64 s[30:31]
 ;
 ; EG-LABEL: v_ctlz_zero_undef_v2i8:
 ; EG:       ; %bb.0:
@@ -2569,11 +2536,9 @@ define <2 x i8> @v_ctlz_zero_undef_v2i8(<2 x i8> %val) {
 ; GFX9-GISEL-LABEL: v_ctlz_zero_undef_v2i8:
 ; GFX9-GISEL:       ; %bb.0:
 ; GFX9-GISEL-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
-; GFX9-GISEL-NEXT:    v_ffbh_u32_sdwa v0, v0 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:BYTE_0
-; GFX9-GISEL-NEXT:    v_ffbh_u32_sdwa v1, v1 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:BYTE_0
-; GFX9-GISEL-NEXT:    v_subrev_u32_e32 v0, 24, v0
-; GFX9-GISEL-NEXT:    v_subrev_u32_e32 v1, 24, v1
-; GFX9-GISEL-NEXT:    s_setpc_b64 s[30:31]
+; GFX9-GISEL-NEXT:    v_ffbh_u32_sdwa v0, v0 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:BYTE_3
+; GFX9-GISEL-NEXT:  	v_ffbh_u32_sdwa v1, v1 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:BYTE_3
+; GFX9-GISEL-NEXT:  	s_setpc_b64 s[30:31]
   %ctlz = call <2 x i8> @llvm.ctlz.v2i8(<2 x i8> %val, i1 true)
   ret <2 x i8> %ctlz
 }
@@ -2614,13 +2579,11 @@ define <2 x i7> @v_ctlz_zero_undef_v2i7(<2 x i7> %val) {
 ; GFX9-GISEL-LABEL: v_ctlz_zero_undef_v2i7:
 ; GFX9-GISEL:       ; %bb.0:
 ; GFX9-GISEL-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
-; GFX9-GISEL-NEXT:    v_and_b32_e32 v0, 0x7f, v0
-; GFX9-GISEL-NEXT:    v_and_b32_e32 v1, 0x7f, v1
-; GFX9-GISEL-NEXT:    v_ffbh_u32_e32 v0, v0
-; GFX9-GISEL-NEXT:    v_ffbh_u32_e32 v1, v1
-; GFX9-GISEL-NEXT:    v_subrev_u32_e32 v0, 25, v0
-; GFX9-GISEL-NEXT:    v_subrev_u32_e32 v1, 25, v1
-; GFX9-GISEL-NEXT:    s_setpc_b64 s[30:31]
+; GFX9-GISEL-NEXT:    v_lshrrev_b32_e32 v0, 25, v0
+; GFX9-GISEL-NEXT:  	v_lshrrev_b32_e32 v1, 25, v1
+; GFX9-GISEL-NEXT:  	v_ffbh_u32_e32 v0, v0
+; GFX9-GISEL-NEXT:  	v_ffbh_u32_e32 v1, v1
+; GFX9-GISEL-NEXT:  	s_setpc_b64 s[30:31]
   %ctlz = call <2 x i7> @llvm.ctlz.v2i7(<2 x i7> %val, i1 true)
   ret <2 x i7> %ctlz
 }

>From f98d4c791dad57913e266030c20de3bae4e43b83 Mon Sep 17 00:00:00 2001
From: Leon Clark <leoclark at amd.com>
Date: Fri, 17 May 2024 22:36:52 +0100
Subject: [PATCH 11/11] Fix indentation.

---
 llvm/test/CodeGen/AMDGPU/ctlz_zero_undef.ll | 158 ++++++++++----------
 1 file changed, 79 insertions(+), 79 deletions(-)

diff --git a/llvm/test/CodeGen/AMDGPU/ctlz_zero_undef.ll b/llvm/test/CodeGen/AMDGPU/ctlz_zero_undef.ll
index b6e53c9e55174..d94a27e8c0200 100644
--- a/llvm/test/CodeGen/AMDGPU/ctlz_zero_undef.ll
+++ b/llvm/test/CodeGen/AMDGPU/ctlz_zero_undef.ll
@@ -2187,8 +2187,8 @@ define i7 @v_ctlz_zero_undef_i7(i7 %val) {
 ; GFX9-GISEL:       ; %bb.0:
 ; GFX9-GISEL-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
 ; GFX9-GISEL-NEXT:    v_lshrrev_b32_e32 v0, 25, v0
-; GFX9-GISEL-NEXT:  	v_ffbh_u32_e32 v0, v0
-; GFX9-GISEL-NEXT:  	s_setpc_b64 s[30:31]
+; GFX9-GISEL-NEXT:    v_ffbh_u32_e32 v0, v0
+; GFX9-GISEL-NEXT:    s_setpc_b64 s[30:31]
   %ctlz = call i7 @llvm.ctlz.i7(i7 %val, i1 true)
   ret i7 %ctlz
 }
@@ -2275,18 +2275,18 @@ define amdgpu_kernel void @s_ctlz_zero_undef_i18(ptr addrspace(1) noalias %out,
 ; GFX9-GISEL-LABEL: s_ctlz_zero_undef_i18:
 ; GFX9-GISEL:       ; %bb.0:
 ; GFX9-GISEL-NEXT:    s_load_dword s4, s[0:1], 0x2c
-; GFX9-GISEL-NEXT:  	s_load_dwordx2 s[2:3], s[0:1], 0x24
-; GFX9-GISEL-NEXT:  	v_mov_b32_e32 v0, 0
-; GFX9-GISEL-NEXT:  	s_waitcnt lgkmcnt(0)
-; GFX9-GISEL-NEXT:  	s_lshr_b32 s0, s4, 14
-; GFX9-GISEL-NEXT:  	s_flbit_i32_b32 s0, s0
-; GFX9-GISEL-NEXT:  	s_and_b32 s0, s0, 0x3ffff
-; GFX9-GISEL-NEXT:  	s_lshr_b32 s1, s0, 16
-; GFX9-GISEL-NEXT:  	v_mov_b32_e32 v1, s0
-; GFX9-GISEL-NEXT:  	global_store_short v0, v1, s[2:3]
-; GFX9-GISEL-NEXT:  	v_mov_b32_e32 v1, s1
-; GFX9-GISEL-NEXT:  	global_store_byte v0, v1, s[2:3] offset:2
-; GFX9-GISEL-NEXT:  	s_endpgm
+; GFX9-GISEL-NEXT:    s_load_dwordx2 s[2:3], s[0:1], 0x24
+; GFX9-GISEL-NEXT:    v_mov_b32_e32 v0, 0
+; GFX9-GISEL-NEXT:    s_waitcnt lgkmcnt(0)
+; GFX9-GISEL-NEXT:    s_lshr_b32 s0, s4, 14
+; GFX9-GISEL-NEXT:    s_flbit_i32_b32 s0, s0
+; GFX9-GISEL-NEXT:    s_and_b32 s0, s0, 0x3ffff
+; GFX9-GISEL-NEXT:    s_lshr_b32 s1, s0, 16
+; GFX9-GISEL-NEXT:    v_mov_b32_e32 v1, s0
+; GFX9-GISEL-NEXT:    global_store_short v0, v1, s[2:3]
+; GFX9-GISEL-NEXT:    v_mov_b32_e32 v1, s1
+; GFX9-GISEL-NEXT:    global_store_byte v0, v1, s[2:3] offset:2
+; GFX9-GISEL-NEXT:    s_endpgm
   %ctlz = call i18 @llvm.ctlz.i18(i18 %val, i1 true) nounwind readnone
   store i18 %ctlz, ptr addrspace(1) %out, align 4
   ret void
@@ -2318,8 +2318,8 @@ define i18 @v_ctlz_zero_undef_i18(i18 %val) {
 ; GFX9-GISEL:       ; %bb.0:
 ; GFX9-GISEL-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
 ; GFX9-GISEL-NEXT:    v_lshrrev_b32_e32 v0, 14, v0
-; GFX9-GISEL-NEXT:  	v_ffbh_u32_e32 v0, v0
-; GFX9-GISEL-NEXT:  	s_setpc_b64 s[30:31]
+; GFX9-GISEL-NEXT:    v_ffbh_u32_e32 v0, v0
+; GFX9-GISEL-NEXT:    s_setpc_b64 s[30:31]
   %ctlz = call i18 @llvm.ctlz.i18(i18 %val, i1 true)
   ret i18 %ctlz
 }
@@ -2356,10 +2356,10 @@ define <2 x i18> @v_ctlz_zero_undef_v2i18(<2 x i18> %val) {
 ; GFX9-GISEL:       ; %bb.0:
 ; GFX9-GISEL-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
 ; GFX9-GISEL-NEXT:    v_lshrrev_b32_e32 v0, 14, v0
-; GFX9-GISEL-NEXT:  	v_lshrrev_b32_e32 v1, 14, v1
-; GFX9-GISEL-NEXT:  	v_ffbh_u32_e32 v0, v0
-; GFX9-GISEL-NEXT:  	v_ffbh_u32_e32 v1, v1
-; GFX9-GISEL-NEXT:  	s_setpc_b64 s[30:31]
+; GFX9-GISEL-NEXT:    v_lshrrev_b32_e32 v1, 14, v1
+; GFX9-GISEL-NEXT:    v_ffbh_u32_e32 v0, v0
+; GFX9-GISEL-NEXT:    v_ffbh_u32_e32 v1, v1
+; GFX9-GISEL-NEXT:    s_setpc_b64 s[30:31]
   %ctlz = call <2 x i18> @llvm.ctlz.v2i18(<2 x i18> %val, i1 true)
   ret <2 x i18> %ctlz
 }
@@ -2369,12 +2369,12 @@ define <2 x i16> @v_ctlz_zero_undef_v2i16(<2 x i16> %val) {
 ; SI:       ; %bb.0:
 ; SI-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
 ; SI-NEXT:    v_lshlrev_b32_e32 v1, 16, v1
-; SI-NEXT:  	v_lshlrev_b32_e32 v0, 16, v0
-; SI-NEXT:  	v_ffbh_u32_e32 v1, v1
-; SI-NEXT:  	v_lshlrev_b32_e32 v2, 16, v1
-; SI-NEXT:  	v_ffbh_u32_e32 v0, v0
-; SI-NEXT:  	v_or_b32_e32 v0, v0, v2
-; SI-NEXT:  	s_setpc_b64 s[30:31]
+; SI-NEXT:    v_lshlrev_b32_e32 v0, 16, v0
+; SI-NEXT:    v_ffbh_u32_e32 v1, v1
+; SI-NEXT:    v_lshlrev_b32_e32 v2, 16, v1
+; SI-NEXT:    v_ffbh_u32_e32 v0, v0
+; SI-NEXT:    v_or_b32_e32 v0, v0, v2
+; SI-NEXT:    s_setpc_b64 s[30:31]
 ;
 ; VI-LABEL: v_ctlz_zero_undef_v2i16:
 ; VI:       ; %bb.0:
@@ -2395,10 +2395,10 @@ define <2 x i16> @v_ctlz_zero_undef_v2i16(<2 x i16> %val) {
 ; GFX9-GISEL:       ; %bb.0:
 ; GFX9-GISEL-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
 ; GFX9-GISEL-NEXT:    v_ffbh_u32_sdwa v0, v0 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:WORD_1
-; GFX9-GISEL-NEXT:  	s_flbit_i32_b32 s4, 0
-; GFX9-GISEL-NEXT:  	v_and_b32_e32 v0, 0xffff, v0
-; GFX9-GISEL-NEXT:  	v_lshl_or_b32 v0, s4, 16, v0
-; GFX9-GISEL-NEXT:  	s_setpc_b64 s[30:31]
+; GFX9-GISEL-NEXT:    s_flbit_i32_b32 s4, 0
+; GFX9-GISEL-NEXT:    v_and_b32_e32 v0, 0xffff, v0
+; GFX9-GISEL-NEXT:    v_lshl_or_b32 v0, s4, 16, v0
+; GFX9-GISEL-NEXT:    s_setpc_b64 s[30:31]
   %ctlz = call <2 x i16> @llvm.ctlz.v2i16(<2 x i16> %val, i1 true)
   ret <2 x i16> %ctlz
 }
@@ -2408,16 +2408,16 @@ define <3 x i16> @v_ctlz_zero_undef_v3i16(<3 x i16> %val) {
 ; SI:       ; %bb.0:
 ; SI-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
 ; SI-NEXT:    v_lshlrev_b32_e32 v1, 16, v1
-; SI-NEXT:  	v_lshlrev_b32_e32 v0, 16, v0
-; SI-NEXT:  	v_lshlrev_b32_e32 v2, 16, v2
-; SI-NEXT:  	v_ffbh_u32_e32 v1, v1
-; SI-NEXT:  	v_ffbh_u32_e32 v0, v0
-; SI-NEXT:  	v_ffbh_u32_e32 v3, v2
-; SI-NEXT:  	v_lshlrev_b32_e32 v1, 16, v1
-; SI-NEXT:  	v_or_b32_e32 v0, v0, v1
-; SI-NEXT:  	v_or_b32_e32 v2, 0x200000, v3
-; SI-NEXT:  	v_alignbit_b32 v1, v3, v0, 16
-; SI-NEXT:  	s_setpc_b64 s[30:31]
+; SI-NEXT:    v_lshlrev_b32_e32 v0, 16, v0
+; SI-NEXT:    v_lshlrev_b32_e32 v2, 16, v2
+; SI-NEXT:    v_ffbh_u32_e32 v1, v1
+; SI-NEXT:    v_ffbh_u32_e32 v0, v0
+; SI-NEXT:    v_ffbh_u32_e32 v3, v2
+; SI-NEXT:    v_lshlrev_b32_e32 v1, 16, v1
+; SI-NEXT:    v_or_b32_e32 v0, v0, v1
+; SI-NEXT:    v_or_b32_e32 v2, 0x200000, v3
+; SI-NEXT:    v_alignbit_b32 v1, v3, v0, 16
+; SI-NEXT:    s_setpc_b64 s[30:31]
 ;
 ; VI-LABEL: v_ctlz_zero_undef_v3i16:
 ; VI:       ; %bb.0:
@@ -2440,11 +2440,11 @@ define <3 x i16> @v_ctlz_zero_undef_v3i16(<3 x i16> %val) {
 ; GFX9-GISEL:       ; %bb.0:
 ; GFX9-GISEL-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
 ; GFX9-GISEL-NEXT:    v_ffbh_u32_sdwa v0, v0 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:WORD_1
-; GFX9-GISEL-NEXT:  	s_flbit_i32_b32 s4, 0
-; GFX9-GISEL-NEXT:  	v_and_b32_e32 v0, 0xffff, v0
-; GFX9-GISEL-NEXT:  	v_ffbh_u32_sdwa v1, v1 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:WORD_1
-; GFX9-GISEL-NEXT:  	v_lshl_or_b32 v0, s4, 16, v0
-; GFX9-GISEL-NEXT:  	s_setpc_b64 s[30:31]
+; GFX9-GISEL-NEXT:    s_flbit_i32_b32 s4, 0
+; GFX9-GISEL-NEXT:    v_and_b32_e32 v0, 0xffff, v0
+; GFX9-GISEL-NEXT:    v_ffbh_u32_sdwa v1, v1 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:WORD_1
+; GFX9-GISEL-NEXT:    v_lshl_or_b32 v0, s4, 16, v0
+; GFX9-GISEL-NEXT:    s_setpc_b64 s[30:31]
   %ctlz = call <3 x i16> @llvm.ctlz.v3i16(<3 x i16> %val, i1 true)
   ret <3 x i16> %ctlz
 }
@@ -2454,20 +2454,20 @@ define <4 x i16> @v_ctlz_zero_undef_v4i16(<4 x i16> %val) {
 ; SI:       ; %bb.0:
 ; SI-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
 ; SI-NEXT:    v_lshlrev_b32_e32 v3, 16, v3
-; SI-NEXT:  	v_lshlrev_b32_e32 v2, 16, v2
-; SI-NEXT:  	v_lshlrev_b32_e32 v1, 16, v1
-; SI-NEXT:  	v_lshlrev_b32_e32 v0, 16, v0
-; SI-NEXT:  	v_ffbh_u32_e32 v3, v3
-; SI-NEXT:  	v_ffbh_u32_e32 v2, v2
-; SI-NEXT:  	v_ffbh_u32_e32 v1, v1
-; SI-NEXT:  	v_ffbh_u32_e32 v0, v0
-; SI-NEXT:  	v_lshlrev_b32_e32 v3, 16, v3
-; SI-NEXT:  	v_lshlrev_b32_e32 v1, 16, v1
-; SI-NEXT:  	v_or_b32_e32 v2, v2, v3
-; SI-NEXT:  	v_or_b32_e32 v0, v0, v1
-; SI-NEXT:  	v_alignbit_b32 v1, v2, v0, 16
-; SI-NEXT:  	v_lshrrev_b32_e32 v3, 16, v2
-; SI-NEXT:  	s_setpc_b64 s[30:31]
+; SI-NEXT:    v_lshlrev_b32_e32 v2, 16, v2
+; SI-NEXT:    v_lshlrev_b32_e32 v1, 16, v1
+; SI-NEXT:    v_lshlrev_b32_e32 v0, 16, v0
+; SI-NEXT:    v_ffbh_u32_e32 v3, v3
+; SI-NEXT:    v_ffbh_u32_e32 v2, v2
+; SI-NEXT:    v_ffbh_u32_e32 v1, v1
+; SI-NEXT:    v_ffbh_u32_e32 v0, v0
+; SI-NEXT:    v_lshlrev_b32_e32 v3, 16, v3
+; SI-NEXT:    v_lshlrev_b32_e32 v1, 16, v1
+; SI-NEXT:    v_or_b32_e32 v2, v2, v3
+; SI-NEXT:    v_or_b32_e32 v0, v0, v1
+; SI-NEXT:    v_alignbit_b32 v1, v2, v0, 16
+; SI-NEXT:    v_lshrrev_b32_e32 v3, 16, v2
+; SI-NEXT:    s_setpc_b64 s[30:31]
 ;
 ; VI-LABEL: v_ctlz_zero_undef_v4i16:
 ; VI:       ; %bb.0:
@@ -2493,13 +2493,13 @@ define <4 x i16> @v_ctlz_zero_undef_v4i16(<4 x i16> %val) {
 ; GFX9-GISEL:       ; %bb.0:
 ; GFX9-GISEL-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
 ; GFX9-GISEL-NEXT:    v_ffbh_u32_sdwa v0, v0 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:WORD_1
-; GFX9-GISEL-NEXT:  	v_ffbh_u32_sdwa v1, v1 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:WORD_1
-; GFX9-GISEL-NEXT:  	s_flbit_i32_b32 s4, 0
-; GFX9-GISEL-NEXT:  	v_and_b32_e32 v0, 0xffff, v0
-; GFX9-GISEL-NEXT:  	v_and_b32_e32 v1, 0xffff, v1
-; GFX9-GISEL-NEXT:  	v_lshl_or_b32 v0, s4, 16, v0
-; GFX9-GISEL-NEXT:  	v_lshl_or_b32 v1, s4, 16, v1
-; GFX9-GISEL-NEXT:  	s_setpc_b64 s[30:31]
+; GFX9-GISEL-NEXT:    v_ffbh_u32_sdwa v1, v1 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:WORD_1
+; GFX9-GISEL-NEXT:    s_flbit_i32_b32 s4, 0
+; GFX9-GISEL-NEXT:    v_and_b32_e32 v0, 0xffff, v0
+; GFX9-GISEL-NEXT:    v_and_b32_e32 v1, 0xffff, v1
+; GFX9-GISEL-NEXT:    v_lshl_or_b32 v0, s4, 16, v0
+; GFX9-GISEL-NEXT:    v_lshl_or_b32 v1, s4, 16, v1
+; GFX9-GISEL-NEXT:    s_setpc_b64 s[30:31]
   %ctlz = call <4 x i16> @llvm.ctlz.v4i16(<4 x i16> %val, i1 true)
   ret <4 x i16> %ctlz
 }
@@ -2520,13 +2520,13 @@ define <2 x i8> @v_ctlz_zero_undef_v2i8(<2 x i8> %val) {
 ; VI:       ; %bb.0:
 ; VI-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
 ; VI-NEXT:    v_lshlrev_b32_e32 v1, 24, v1
-; VI-NEXT:  	v_ffbh_u32_e32 v1, v1
-; VI-NEXT:  	v_lshlrev_b32_e32 v0, 24, v0
-; VI-NEXT:  	v_lshlrev_b16_e32 v2, 8, v1
-; VI-NEXT:  	v_ffbh_u32_e32 v0, v0
-; VI-NEXT:  	v_or_b32_e32 v0, v0, v2
-; VI-NEXT:  	v_and_b32_e32 v1, 0xff, v1
-; VI-NEXT:  	s_setpc_b64 s[30:31]
+; VI-NEXT:    v_ffbh_u32_e32 v1, v1
+; VI-NEXT:    v_lshlrev_b32_e32 v0, 24, v0
+; VI-NEXT:    v_lshlrev_b16_e32 v2, 8, v1
+; VI-NEXT:    v_ffbh_u32_e32 v0, v0
+; VI-NEXT:    v_or_b32_e32 v0, v0, v2
+; VI-NEXT:    v_and_b32_e32 v1, 0xff, v1
+; VI-NEXT:    s_setpc_b64 s[30:31]
 ;
 ; EG-LABEL: v_ctlz_zero_undef_v2i8:
 ; EG:       ; %bb.0:
@@ -2537,8 +2537,8 @@ define <2 x i8> @v_ctlz_zero_undef_v2i8(<2 x i8> %val) {
 ; GFX9-GISEL:       ; %bb.0:
 ; GFX9-GISEL-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
 ; GFX9-GISEL-NEXT:    v_ffbh_u32_sdwa v0, v0 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:BYTE_3
-; GFX9-GISEL-NEXT:  	v_ffbh_u32_sdwa v1, v1 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:BYTE_3
-; GFX9-GISEL-NEXT:  	s_setpc_b64 s[30:31]
+; GFX9-GISEL-NEXT:    v_ffbh_u32_sdwa v1, v1 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:BYTE_3
+; GFX9-GISEL-NEXT:    s_setpc_b64 s[30:31]
   %ctlz = call <2 x i8> @llvm.ctlz.v2i8(<2 x i8> %val, i1 true)
   ret <2 x i8> %ctlz
 }
@@ -2580,10 +2580,10 @@ define <2 x i7> @v_ctlz_zero_undef_v2i7(<2 x i7> %val) {
 ; GFX9-GISEL:       ; %bb.0:
 ; GFX9-GISEL-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
 ; GFX9-GISEL-NEXT:    v_lshrrev_b32_e32 v0, 25, v0
-; GFX9-GISEL-NEXT:  	v_lshrrev_b32_e32 v1, 25, v1
-; GFX9-GISEL-NEXT:  	v_ffbh_u32_e32 v0, v0
-; GFX9-GISEL-NEXT:  	v_ffbh_u32_e32 v1, v1
-; GFX9-GISEL-NEXT:  	s_setpc_b64 s[30:31]
+; GFX9-GISEL-NEXT:    v_lshrrev_b32_e32 v1, 25, v1
+; GFX9-GISEL-NEXT:    v_ffbh_u32_e32 v0, v0
+; GFX9-GISEL-NEXT:    v_ffbh_u32_e32 v1, v1
+; GFX9-GISEL-NEXT:    s_setpc_b64 s[30:31]
   %ctlz = call <2 x i7> @llvm.ctlz.v2i7(<2 x i7> %val, i1 true)
   ret <2 x i7> %ctlz
 }



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