[PATCH] D130992: [AMDGPU] Take advantage of VOP3 literals in convertToThreeAddress

[Jay Foad via Phabricator via llvm-commits]

foad created this revision.
foad added reviewers: AMDGPU, Joe_Nash.
Herald added subscribers: kosarev, kerbowa, hiraditya, t-tye, tpr, dstuttard, yaxunl, nhaehnle, jvesely, kzhuravl, arsenm.
Herald added a project: All.
foad requested review of this revision.
Herald added subscribers: llvm-commits, wdng.
Herald added a project: LLVM.

This improves a corner case where v_fmac can be converted to v_fma on
GFX10+ even if it has a literal operand.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D130992

Files:
  llvm/lib/Target/AMDGPU/SIInstrInfo.cpp
  llvm/test/CodeGen/AMDGPU/llvm.amdgcn.fma.legacy.ll


Index: llvm/test/CodeGen/AMDGPU/llvm.amdgcn.fma.legacy.ll
===================================================================
--- llvm/test/CodeGen/AMDGPU/llvm.amdgcn.fma.legacy.ll
+++ llvm/test/CodeGen/AMDGPU/llvm.amdgcn.fma.legacy.ll
@@ -34,17 +34,14 @@
 ; GFX10:       ; %bb.0:
 ; GFX10-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
 ; GFX10-NEXT:    s_waitcnt_vscnt null, 0x0
-; GFX10-NEXT:    v_fmac_legacy_f32_e32 v1, 0x41200000, v0
-; GFX10-NEXT:    v_mov_b32_e32 v0, v1
+; GFX10-NEXT:    v_fma_legacy_f32 v0, 0x41200000, v0, v1
 ; GFX10-NEXT:    s_setpc_b64 s[30:31]
 ;
 ; GFX11-LABEL: v_fma_imm:
 ; GFX11:       ; %bb.0:
 ; GFX11-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
 ; GFX11-NEXT:    s_waitcnt_vscnt null, 0x0
-; GFX11-NEXT:    v_fmac_dx9_zero_f32_e32 v1, 0x41200000, v0
-; GFX11-NEXT:    s_delay_alu instid0(VALU_DEP_1)
-; GFX11-NEXT:    v_mov_b32_e32 v0, v1
+; GFX11-NEXT:    v_fma_dx9_zero_f32 v0, 0x41200000, v0, v1
 ; GFX11-NEXT:    s_setpc_b64 s[30:31]
   %fma = call float @llvm.amdgcn.fma.legacy(float %a, float 10.0, float %c)
   ret float %fma
Index: llvm/lib/Target/AMDGPU/SIInstrInfo.cpp
===================================================================
--- llvm/lib/Target/AMDGPU/SIInstrInfo.cpp
+++ llvm/lib/Target/AMDGPU/SIInstrInfo.cpp
@@ -3416,9 +3416,8 @@
   }
 
   // VOP2 mac/fmac with a literal operand cannot be converted to VOP3 mad/fma
-  // because VOP3 does not allow a literal operand.
-  // TODO: Remove this restriction for GFX10.
-  if (Src0Literal)
+  // if VOP3 does not allow a literal operand.
+  if (Src0Literal && !ST.hasVOP3Literal())
     return nullptr;
 
   unsigned NewOpc = IsFMA ? IsF16 ? AMDGPU::V_FMA_F16_gfx9_e64


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D130992.449304.patch
Type: text/x-patch
Size: 1686 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20220802/7a0b0a45/attachment.bin>