[llvm] [AMDGPU] Set hasSideEffects=0 for SALU psuedos (PR #134487)

via llvm-commits llvm-commits at lists.llvm.org
Thu Apr 10 04:07:10 PDT 2025


https://github.com/amansharma612 updated https://github.com/llvm/llvm-project/pull/134487

>From c0cc335b62776757d7258024641292cb24faae6f Mon Sep 17 00:00:00 2001
From: Aman Sharma <210100011 at iitb.ac.in>
Date: Sat, 5 Apr 2025 14:02:57 +0530
Subject: [PATCH 1/2] [AMDGPU] Set hasSideEffects=0 for SALU psuedos

---
 llvm/lib/Target/AMDGPU/SIInstructions.td  | 16 ++++++++++++----
 llvm/lib/Target/AMDGPU/SOPInstructions.td |  8 ++++++--
 2 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/llvm/lib/Target/AMDGPU/SIInstructions.td b/llvm/lib/Target/AMDGPU/SIInstructions.td
index 9051db0c01ed1..e78a29e36b358 100644
--- a/llvm/lib/Target/AMDGPU/SIInstructions.td
+++ b/llvm/lib/Target/AMDGPU/SIInstructions.td
@@ -340,19 +340,27 @@ def S_SUB_U64_PSEUDO : SPseudoInstSI <
 
 def S_ADD_CO_PSEUDO : SPseudoInstSI <
   (outs SReg_32:$sdst, SSrc_i1:$scc_out), (ins SSrc_b32:$src0, SSrc_b32:$src1, SSrc_i1:$scc_in)
->;
+>{
+    let hasSideEffects = 0;
+}
 
 def S_SUB_CO_PSEUDO : SPseudoInstSI <
   (outs SReg_32:$sdst, SSrc_i1:$scc_out), (ins SSrc_b32:$src0, SSrc_b32:$src1, SSrc_i1:$scc_in)
->;
+>{
+    let hasSideEffects = 0;
+}
 
 def S_UADDO_PSEUDO : SPseudoInstSI <
   (outs SReg_32:$sdst, SSrc_i1:$scc_out), (ins SSrc_b32:$src0, SSrc_b32:$src1)
->;
+>{
+    let hasSideEffects = 0;
+}
 
 def S_USUBO_PSEUDO : SPseudoInstSI <
   (outs SReg_32:$sdst, SSrc_i1:$scc_out), (ins SSrc_b32:$src0, SSrc_b32:$src1)
->;
+>{
+    let hasSideEffects = 0;
+}
 
 let OtherPredicates = [HasShaderCyclesHiLoRegisters] in
 def GET_SHADERCYCLESHILO : SPseudoInstSI<
diff --git a/llvm/lib/Target/AMDGPU/SOPInstructions.td b/llvm/lib/Target/AMDGPU/SOPInstructions.td
index 73f4655f735a2..be63bc4a745eb 100644
--- a/llvm/lib/Target/AMDGPU/SOPInstructions.td
+++ b/llvm/lib/Target/AMDGPU/SOPInstructions.td
@@ -665,12 +665,16 @@ let SubtargetPredicate = isGFX12Plus in {
   // The higher 32-bits of the inputs contain the sign extension bits.
   def S_MUL_I64_I32_PSEUDO : SPseudoInstSI <
     (outs SReg_64:$sdst), (ins SSrc_b64:$src0, SSrc_b64:$src1)
-  >;
+  >{
+      let hasSideEffects = 0;
+  }
 
   // The higher 32-bits of the inputs are zero.
   def S_MUL_U64_U32_PSEUDO : SPseudoInstSI <
     (outs SReg_64:$sdst), (ins SSrc_b64:$src0, SSrc_b64:$src1)
-  >;
+  >{
+    let hasSideEffects = 0;
+  }
 
 } // End SubtargetPredicate = isGFX12Plus
 

>From baddce94d0f96c4c4b725ac5a1da42e60e1b59f5 Mon Sep 17 00:00:00 2001
From: Aman Sharma <210100011 at iitb.ac.in>
Date: Mon, 7 Apr 2025 12:53:57 +0530
Subject: [PATCH 2/2] Style fix

---
 llvm/lib/Target/AMDGPU/SIInstructions.td  | 36 ++++++++++-------------
 llvm/lib/Target/AMDGPU/SOPInstructions.td | 18 +++++-------
 llvm/test/CodeGen/AMDGPU/mul.ll           | 10 +++----
 3 files changed, 28 insertions(+), 36 deletions(-)

diff --git a/llvm/lib/Target/AMDGPU/SIInstructions.td b/llvm/lib/Target/AMDGPU/SIInstructions.td
index e78a29e36b358..0e089e76e9722 100644
--- a/llvm/lib/Target/AMDGPU/SIInstructions.td
+++ b/llvm/lib/Target/AMDGPU/SIInstructions.td
@@ -231,7 +231,7 @@ def EXIT_STRICT_WQM : SPseudoInstSI <(outs SReg_1:$sdst), (ins SReg_1:$src0)> {
   let mayStore = 0;
 }
 
-let usesCustomInserter = 1 in {
+let usesCustomInserter = 1, hasSideEffects = 0 in {
 let WaveSizePredicate = isWave32 in
 def S_INVERSE_BALLOT_U32 : SPseudoInstSI<
   (outs SReg_32:$sdst), (ins SSrc_b32:$mask),
@@ -243,7 +243,7 @@ def S_INVERSE_BALLOT_U64 : SPseudoInstSI<
   (outs SReg_64:$sdst), (ins SSrc_b64:$mask),
   [(set i1:$sdst, (int_amdgcn_inverse_ballot i64:$mask))]
 >;
-} // End usesCustomInserter = 1
+} // End usesCustomInserter = 1, hasSideEffects = 0
 
 let WaveSizePredicate = isWave32 in
   def : GCNPat <
@@ -338,28 +338,22 @@ def S_SUB_U64_PSEUDO : SPseudoInstSI <
   [(set SReg_64:$sdst, (UniformBinFrag<sub> i64:$src0, i64:$src1))]
 >;
 
-def S_ADD_CO_PSEUDO : SPseudoInstSI <
-  (outs SReg_32:$sdst, SSrc_i1:$scc_out), (ins SSrc_b32:$src0, SSrc_b32:$src1, SSrc_i1:$scc_in)
->{
-    let hasSideEffects = 0;
-}
+let hasSideEffects = 0 in {
+  def S_ADD_CO_PSEUDO : SPseudoInstSI <
+    (outs SReg_32:$sdst, SSrc_i1:$scc_out), (ins SSrc_b32:$src0, SSrc_b32:$src1, SSrc_i1:$scc_in)
+  >;
 
-def S_SUB_CO_PSEUDO : SPseudoInstSI <
-  (outs SReg_32:$sdst, SSrc_i1:$scc_out), (ins SSrc_b32:$src0, SSrc_b32:$src1, SSrc_i1:$scc_in)
->{
-    let hasSideEffects = 0;
-}
+  def S_SUB_CO_PSEUDO : SPseudoInstSI <
+    (outs SReg_32:$sdst, SSrc_i1:$scc_out), (ins SSrc_b32:$src0, SSrc_b32:$src1, SSrc_i1:$scc_in)
+  >;
 
-def S_UADDO_PSEUDO : SPseudoInstSI <
-  (outs SReg_32:$sdst, SSrc_i1:$scc_out), (ins SSrc_b32:$src0, SSrc_b32:$src1)
->{
-    let hasSideEffects = 0;
-}
+  def S_UADDO_PSEUDO : SPseudoInstSI <
+    (outs SReg_32:$sdst, SSrc_i1:$scc_out), (ins SSrc_b32:$src0, SSrc_b32:$src1)
+  >;
 
-def S_USUBO_PSEUDO : SPseudoInstSI <
-  (outs SReg_32:$sdst, SSrc_i1:$scc_out), (ins SSrc_b32:$src0, SSrc_b32:$src1)
->{
-    let hasSideEffects = 0;
+  def S_USUBO_PSEUDO : SPseudoInstSI <
+    (outs SReg_32:$sdst, SSrc_i1:$scc_out), (ins SSrc_b32:$src0, SSrc_b32:$src1)
+  >;
 }
 
 let OtherPredicates = [HasShaderCyclesHiLoRegisters] in
diff --git a/llvm/lib/Target/AMDGPU/SOPInstructions.td b/llvm/lib/Target/AMDGPU/SOPInstructions.td
index be63bc4a745eb..3d3f1ba3f5170 100644
--- a/llvm/lib/Target/AMDGPU/SOPInstructions.td
+++ b/llvm/lib/Target/AMDGPU/SOPInstructions.td
@@ -663,17 +663,15 @@ let SubtargetPredicate = isGFX12Plus in {
   }
 
   // The higher 32-bits of the inputs contain the sign extension bits.
-  def S_MUL_I64_I32_PSEUDO : SPseudoInstSI <
-    (outs SReg_64:$sdst), (ins SSrc_b64:$src0, SSrc_b64:$src1)
-  >{
-      let hasSideEffects = 0;
-  }
+  let hasSideEffects = 0 in {
+    def S_MUL_I64_I32_PSEUDO : SPseudoInstSI <
+      (outs SReg_64:$sdst), (ins SSrc_b64:$src0, SSrc_b64:$src1)
+    >;
 
-  // The higher 32-bits of the inputs are zero.
-  def S_MUL_U64_U32_PSEUDO : SPseudoInstSI <
-    (outs SReg_64:$sdst), (ins SSrc_b64:$src0, SSrc_b64:$src1)
-  >{
-    let hasSideEffects = 0;
+    // The higher 32-bits of the inputs are zero.
+    def S_MUL_U64_U32_PSEUDO : SPseudoInstSI <
+      (outs SReg_64:$sdst), (ins SSrc_b64:$src0, SSrc_b64:$src1)
+    >;
   }
 
 } // End SubtargetPredicate = isGFX12Plus
diff --git a/llvm/test/CodeGen/AMDGPU/mul.ll b/llvm/test/CodeGen/AMDGPU/mul.ll
index 7dd45181a8356..896f48a9215b9 100644
--- a/llvm/test/CodeGen/AMDGPU/mul.ll
+++ b/llvm/test/CodeGen/AMDGPU/mul.ll
@@ -2850,17 +2850,17 @@ define amdgpu_kernel void @s_mul_i128(ptr addrspace(1) %out, [8 x i32], i128 %a,
 ; GFX12-NEXT:    s_mov_b32 s5, s3
 ; GFX12-NEXT:    s_mov_b32 s17, s3
 ; GFX12-NEXT:    s_mov_b32 s19, s3
-; GFX12-NEXT:    s_mov_b32 s24, s3
+; GFX12-NEXT:    s_mov_b32 s20, s3
 ; GFX12-NEXT:    s_wait_kmcnt 0x0
 ; GFX12-NEXT:    s_mov_b32 s2, s8
 ; GFX12-NEXT:    s_mov_b32 s6, s12
 ; GFX12-NEXT:    s_mov_b32 s4, s13
 ; GFX12-NEXT:    s_mul_u64 s[22:23], s[6:7], s[2:3]
-; GFX12-NEXT:    s_mul_u64 s[20:21], s[4:5], s[2:3]
+; GFX12-NEXT:    s_mul_u64 s[24:25], s[4:5], s[2:3]
 ; GFX12-NEXT:    s_mov_b32 s2, s23
 ; GFX12-NEXT:    s_mov_b32 s16, s9
 ; GFX12-NEXT:    s_mul_u64 s[10:11], s[10:11], s[12:13]
-; GFX12-NEXT:    s_add_nc_u64 s[12:13], s[20:21], s[2:3]
+; GFX12-NEXT:    s_add_nc_u64 s[12:13], s[24:25], s[2:3]
 ; GFX12-NEXT:    s_mul_u64 s[6:7], s[6:7], s[16:17]
 ; GFX12-NEXT:    s_mov_b32 s2, s13
 ; GFX12-NEXT:    s_mov_b32 s13, s3
@@ -2871,9 +2871,9 @@ define amdgpu_kernel void @s_mul_i128(ptr addrspace(1) %out, [8 x i32], i128 %a,
 ; GFX12-NEXT:    s_mov_b32 s23, s3
 ; GFX12-NEXT:    s_add_nc_u64 s[2:3], s[2:3], s[18:19]
 ; GFX12-NEXT:    s_add_nc_u64 s[8:9], s[10:11], s[8:9]
-; GFX12-NEXT:    s_mov_b32 s25, s6
+; GFX12-NEXT:    s_mov_b32 s21, s6
 ; GFX12-NEXT:    s_add_nc_u64 s[2:3], s[4:5], s[2:3]
-; GFX12-NEXT:    s_or_b64 s[6:7], s[22:23], s[24:25]
+; GFX12-NEXT:    s_or_b64 s[6:7], s[22:23], s[20:21]
 ; GFX12-NEXT:    s_add_nc_u64 s[2:3], s[2:3], s[8:9]
 ; GFX12-NEXT:    v_dual_mov_b32 v0, s6 :: v_dual_mov_b32 v1, s7
 ; GFX12-NEXT:    v_dual_mov_b32 v2, s2 :: v_dual_mov_b32 v3, s3



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