[llvm] r325677 - AMDGPU: Do not combine loads/store across physreg defs
Nicolai Haehnle via llvm-commits
llvm-commits at lists.llvm.org
Wed Feb 21 05:31:35 PST 2018
Author: nha
Date: Wed Feb 21 05:31:35 2018
New Revision: 325677
URL: http://llvm.org/viewvc/llvm-project?rev=325677&view=rev
Log:
AMDGPU: Do not combine loads/store across physreg defs
Summary:
Since this pass operates on machine SSA form, this should only really
affect M0 in practice.
Fixes various piglit variable-indexing/vs-varying-array-mat4-index-*
Change-Id: Ib2a1dc3a8d7b08225a8da49a86f533faa0986aa8
Fixes: r317751 ("AMDGPU: Merge S_BUFFER_LOAD_DWORD_IMM into x2, x4")
Reviewers: arsenm, mareko, rampitec
Subscribers: kzhuravl, wdng, yaxunl, dstuttard, tpr, t-tye, llvm-commits
Differential Revision: https://reviews.llvm.org/D40343
Modified:
llvm/trunk/lib/Target/AMDGPU/SILoadStoreOptimizer.cpp
llvm/trunk/test/CodeGen/AMDGPU/ds_read2.ll
llvm/trunk/test/CodeGen/AMDGPU/llvm.amdgcn.interp.ll
llvm/trunk/test/CodeGen/AMDGPU/smrd.ll
Modified: llvm/trunk/lib/Target/AMDGPU/SILoadStoreOptimizer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AMDGPU/SILoadStoreOptimizer.cpp?rev=325677&r1=325676&r2=325677&view=diff
==============================================================================
--- llvm/trunk/lib/Target/AMDGPU/SILoadStoreOptimizer.cpp (original)
+++ llvm/trunk/lib/Target/AMDGPU/SILoadStoreOptimizer.cpp Wed Feb 21 05:31:35 2018
@@ -228,6 +228,16 @@ canMoveInstsAcrossMemOp(MachineInstr &Me
return true;
}
+static bool
+hasPhysRegDef(MachineInstr &MI) {
+ for (const MachineOperand &Def : MI.defs()) {
+ if (Def.isReg() &&
+ TargetRegisterInfo::isPhysicalRegister(Def.getReg()))
+ return true;
+ }
+ return false;
+}
+
bool SILoadStoreOptimizer::offsetsCanBeCombined(CombineInfo &CI) {
// XXX - Would the same offset be OK? Is there any reason this would happen or
// be useful?
@@ -350,6 +360,13 @@ bool SILoadStoreOptimizer::findMatchingI
return false;
}
+ if (hasPhysRegDef(*MBBI)) {
+ // We could re-order this instruction in theory, but it would require
+ // tracking physreg defs and uses. This should only affect M0 in
+ // practice.
+ return false;
+ }
+
if (MBBI->mayLoadOrStore() &&
(!memAccessesCanBeReordered(*CI.I, *MBBI, TII, AA) ||
!canMoveInstsAcrossMemOp(*MBBI, CI.InstsToMove, TII, AA))) {
@@ -437,7 +454,8 @@ bool SILoadStoreOptimizer::findMatchingI
// down past this instruction.
// check if we can move I across MBBI and if we can move all I's users
if (!memAccessesCanBeReordered(*CI.I, *MBBI, TII, AA) ||
- !canMoveInstsAcrossMemOp(*MBBI, CI.InstsToMove, TII, AA))
+ !canMoveInstsAcrossMemOp(*MBBI, CI.InstsToMove, TII, AA) ||
+ hasPhysRegDef(*MBBI))
break;
}
return false;
Modified: llvm/trunk/test/CodeGen/AMDGPU/ds_read2.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AMDGPU/ds_read2.ll?rev=325677&r1=325676&r2=325677&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/AMDGPU/ds_read2.ll (original)
+++ llvm/trunk/test/CodeGen/AMDGPU/ds_read2.ll Wed Feb 21 05:31:35 2018
@@ -613,6 +613,24 @@ bb:
ret void
}
+; GCN-LABEL: ds_read_call_read:
+; GCN: ds_read_b32
+; GCN: s_swappc_b64
+; GCN: ds_read_b32
+define amdgpu_kernel void @ds_read_call_read(i32 addrspace(1)* %out, i32 addrspace(3)* %arg) {
+ %x = call i32 @llvm.amdgcn.workitem.id.x()
+ %arrayidx0 = getelementptr i32, i32 addrspace(3)* %arg, i32 %x
+ %arrayidx1 = getelementptr i32, i32 addrspace(3)* %arrayidx0, i32 1
+ %v0 = load i32, i32 addrspace(3)* %arrayidx0, align 4
+ call void @void_func_void()
+ %v1 = load i32, i32 addrspace(3)* %arrayidx1, align 4
+ %r = add i32 %v0, %v1
+ store i32 %r, i32 addrspace(1)* %out, align 4
+ ret void
+}
+
+declare void @void_func_void() #3
+
declare i32 @llvm.amdgcn.workgroup.id.x() #1
declare i32 @llvm.amdgcn.workgroup.id.y() #1
declare i32 @llvm.amdgcn.workitem.id.x() #1
@@ -623,3 +641,4 @@ declare void @llvm.amdgcn.s.barrier() #2
attributes #0 = { nounwind }
attributes #1 = { nounwind readnone speculatable }
attributes #2 = { convergent nounwind }
+attributes #3 = { nounwind noinline }
Modified: llvm/trunk/test/CodeGen/AMDGPU/llvm.amdgcn.interp.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AMDGPU/llvm.amdgcn.interp.ll?rev=325677&r1=325676&r2=325677&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/AMDGPU/llvm.amdgcn.interp.ll (original)
+++ llvm/trunk/test/CodeGen/AMDGPU/llvm.amdgcn.interp.ll Wed Feb 21 05:31:35 2018
@@ -160,21 +160,25 @@ bb:
; SI won't merge ds memory operations, because of the signed offset bug, so
; we only have check lines for VI.
-; VI-LABEL: v_interp_readnone:
-; VI: s_mov_b32 m0, 0
-; VI-DAG: v_mov_b32_e32 [[ZERO:v[0-9]+]], 0
-; VI-DAG: v_interp_mov_f32 v{{[0-9]+}}, p0, attr0.x{{$}}
-; VI: s_mov_b32 m0, -1{{$}}
-; VI: ds_write2_b32 v{{[0-9]+}}, [[ZERO]], [[ZERO]] offset1:4
-define amdgpu_ps void @v_interp_readnone(float addrspace(3)* %lds) #0 {
-bb:
- store float 0.000000e+00, float addrspace(3)* %lds
- %tmp1 = call float @llvm.amdgcn.interp.mov(i32 2, i32 0, i32 0, i32 0)
- %tmp2 = getelementptr float, float addrspace(3)* %lds, i32 4
- store float 0.000000e+00, float addrspace(3)* %tmp2
- call void @llvm.amdgcn.exp.f32(i32 0, i32 15, float %tmp1, float %tmp1, float %tmp1, float %tmp1, i1 true, i1 true) #0
- ret void
-}
+;
+; TODO: VI won't merge them either, because we are conservative about moving
+; instructions past changes to physregs.
+;
+; TODO-VI-LABEL: v_interp_readnone:
+; TODO-VI: s_mov_b32 m0, 0
+; TODO-VI-DAG: v_mov_b32_e32 [[ZERO:v[0-9]+]], 0
+; TODO-VI-DAG: v_interp_mov_f32 v{{[0-9]+}}, p0, attr0.x{{$}}
+; TODO-VI: s_mov_b32 m0, -1{{$}}
+; TODO-VI: ds_write2_b32 v{{[0-9]+}}, [[ZERO]], [[ZERO]] offset1:4
+;define amdgpu_ps void @v_interp_readnone(float addrspace(3)* %lds) #0 {
+;bb:
+; store float 0.000000e+00, float addrspace(3)* %lds
+; %tmp1 = call float @llvm.amdgcn.interp.mov(i32 2, i32 0, i32 0, i32 0)
+; %tmp2 = getelementptr float, float addrspace(3)* %lds, i32 4
+; store float 0.000000e+00, float addrspace(3)* %tmp2
+; call void @llvm.amdgcn.exp.f32(i32 0, i32 15, float %tmp1, float %tmp1, float %tmp1, float %tmp1, i1 true, i1 true) #0
+; ret void
+;}
; Thest that v_interp_p1 uses different source and destination registers
; on 16 bank LDS chips.
Modified: llvm/trunk/test/CodeGen/AMDGPU/smrd.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AMDGPU/smrd.ll?rev=325677&r1=325676&r2=325677&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/AMDGPU/smrd.ll (original)
+++ llvm/trunk/test/CodeGen/AMDGPU/smrd.ll Wed Feb 21 05:31:35 2018
@@ -232,6 +232,48 @@ main_body:
ret void
}
+; GCN-LABEL: {{^}}smrd_imm_nomerge_m0:
+;
+; In principle we could merge the loads here as well, but it would require
+; careful tracking of physical registers since both v_interp* and v_movrel*
+; instructions (or gpr idx mode) use M0.
+;
+; GCN: s_buffer_load_dword
+; GCN: s_buffer_load_dword
+define amdgpu_ps float @smrd_imm_nomerge_m0(<4 x i32> inreg %desc, i32 inreg %prim, float %u, float %v) #0 {
+main_body:
+ %idx1.f = call float @llvm.SI.load.const.v4i32(<4 x i32> %desc, i32 0)
+ %idx1 = bitcast float %idx1.f to i32
+
+ %v0.x1 = call nsz float @llvm.amdgcn.interp.p1(float %u, i32 0, i32 0, i32 %prim)
+ %v0.x = call nsz float @llvm.amdgcn.interp.p2(float %v0.x1, float %v, i32 0, i32 0, i32 %prim)
+ %v0.y1 = call nsz float @llvm.amdgcn.interp.p1(float %u, i32 0, i32 1, i32 %prim)
+ %v0.y = call nsz float @llvm.amdgcn.interp.p2(float %v0.y1, float %v, i32 0, i32 1, i32 %prim)
+ %v0.z1 = call nsz float @llvm.amdgcn.interp.p1(float %u, i32 0, i32 2, i32 %prim)
+ %v0.z = call nsz float @llvm.amdgcn.interp.p2(float %v0.z1, float %v, i32 0, i32 2, i32 %prim)
+ %v0.tmp0 = insertelement <3 x float> undef, float %v0.x, i32 0
+ %v0.tmp1 = insertelement <3 x float> %v0.tmp0, float %v0.y, i32 1
+ %v0 = insertelement <3 x float> %v0.tmp1, float %v0.z, i32 2
+ %a = extractelement <3 x float> %v0, i32 %idx1
+
+ %v1.x1 = call nsz float @llvm.amdgcn.interp.p1(float %u, i32 1, i32 0, i32 %prim)
+ %v1.x = call nsz float @llvm.amdgcn.interp.p2(float %v1.x1, float %v, i32 1, i32 0, i32 %prim)
+ %v1.y1 = call nsz float @llvm.amdgcn.interp.p1(float %u, i32 1, i32 1, i32 %prim)
+ %v1.y = call nsz float @llvm.amdgcn.interp.p2(float %v1.y1, float %v, i32 1, i32 1, i32 %prim)
+ %v1.z1 = call nsz float @llvm.amdgcn.interp.p1(float %u, i32 1, i32 2, i32 %prim)
+ %v1.z = call nsz float @llvm.amdgcn.interp.p2(float %v1.z1, float %v, i32 1, i32 2, i32 %prim)
+ %v1.tmp0 = insertelement <3 x float> undef, float %v0.x, i32 0
+ %v1.tmp1 = insertelement <3 x float> %v0.tmp0, float %v0.y, i32 1
+ %v1 = insertelement <3 x float> %v0.tmp1, float %v0.z, i32 2
+
+ %b = extractelement <3 x float> %v1, i32 %idx1
+ %c = call float @llvm.SI.load.const.v4i32(<4 x i32> %desc, i32 4)
+
+ %res.tmp = fadd float %a, %b
+ %res = fadd float %res.tmp, %c
+ ret float %res
+}
+
; GCN-LABEL: {{^}}smrd_vgpr_merged:
; GCN-NEXT: %bb.
; GCN-NEXT: buffer_load_dwordx4 v[{{[0-9]}}:{{[0-9]}}], v0, s[0:3], 0 offen offset:4
@@ -289,8 +331,11 @@ ret_block:
declare void @llvm.amdgcn.exp.f32(i32, i32, float, float, float, float, i1, i1) #0
declare float @llvm.SI.load.const.v4i32(<4 x i32>, i32) #1
+declare float @llvm.amdgcn.interp.p1(float, i32, i32, i32) #2
+declare float @llvm.amdgcn.interp.p2(float, float, i32, i32, i32) #2
attributes #0 = { nounwind }
attributes #1 = { nounwind readnone }
+attributes #2 = { nounwind readnone speculatable }
!0 = !{}
More information about the llvm-commits
mailing list