[llvm] 4b4bc1e - [GlobalISel] Do not generate illegal G_SEXTLOADs after legalization
Konstantin Schwarz via llvm-commits
llvm-commits at lists.llvm.org
Wed Aug 25 01:13:57 PDT 2021
Author: Konstantin Schwarz
Date: 2021-08-25T10:13:39+02:00
New Revision: 4b4bc1ea16dec58e828ec3a0154046b10ec69242
URL: https://github.com/llvm/llvm-project/commit/4b4bc1ea16dec58e828ec3a0154046b10ec69242
DIFF: https://github.com/llvm/llvm-project/commit/4b4bc1ea16dec58e828ec3a0154046b10ec69242.diff
LOG: [GlobalISel] Do not generate illegal G_SEXTLOADs after legalization
The sext_inreg_of_load combine did not have the isLegalOrBeforeLegalizer check,
leading to the generation of potentially illegal G_SEXTLOADs when run after legalization.
Reviewed By: foad
Differential Revision: https://reviews.llvm.org/D108626
Added:
llvm/test/CodeGen/AMDGPU/GlobalISel/postlegalizer-combiner-sextload-from-sextinreg.mir
Modified:
llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp
Removed:
################################################################################
diff --git a/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp
index 949ecacbffd90..34322cb22d25c 100644
--- a/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp
@@ -722,6 +722,18 @@ bool CombinerHelper::matchSextInRegOfLoad(
// anyway for most targets.
if (!isPowerOf2_32(NewSizeBits))
return false;
+
+ const MachineMemOperand &MMO = LoadDef->getMMO();
+ LegalityQuery::MemDesc MMDesc;
+ MMDesc.MemoryTy = LLT::scalar(NewSizeBits);
+ MMDesc.AlignInBits = MMO.getAlign().value() * 8;
+ MMDesc.Ordering = MMO.getSuccessOrdering();
+ if (!isLegalOrBeforeLegalizer({TargetOpcode::G_SEXTLOAD,
+ {MRI.getType(LoadDef->getDstReg()),
+ MRI.getType(LoadDef->getPointerReg())},
+ {MMDesc}}))
+ return false;
+
MatchInfo = std::make_tuple(LoadDef->getDstReg(), NewSizeBits);
return true;
}
diff --git a/llvm/test/CodeGen/AMDGPU/GlobalISel/postlegalizer-combiner-sextload-from-sextinreg.mir b/llvm/test/CodeGen/AMDGPU/GlobalISel/postlegalizer-combiner-sextload-from-sextinreg.mir
new file mode 100644
index 0000000000000..067158e1c66d2
--- /dev/null
+++ b/llvm/test/CodeGen/AMDGPU/GlobalISel/postlegalizer-combiner-sextload-from-sextinreg.mir
@@ -0,0 +1,22 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
+# RUN: llc -global-isel -mtriple=amdgcn-amd-amdhsa -mcpu=gfx900 -run-pass=amdgpu-postlegalizer-combiner -verify-machineinstrs -o - %s | FileCheck %s
+
+# Post-legalizer should not generate illegal extending loads
+---
+name: sextload_from_inreg
+tracksRegLiveness: true
+legalized: true
+body: |
+ bb.0:
+ liveins: $vgpr0_vgpr1
+ ; CHECK-LABEL: name: sextload_from_inreg
+ ; CHECK: liveins: $vgpr0_vgpr1
+ ; CHECK: [[COPY:%[0-9]+]]:_(p1) = COPY $vgpr0_vgpr1
+ ; CHECK: [[LOAD:%[0-9]+]]:_(s64) = G_LOAD [[COPY]](p1) :: (load (s64), addrspace 1)
+ ; CHECK: [[SEXT_INREG:%[0-9]+]]:_(s64) = G_SEXT_INREG [[LOAD]], 8
+ ; CHECK: $vgpr0_vgpr1 = COPY [[SEXT_INREG]](s64)
+ %0:_(p1) = COPY $vgpr0_vgpr1
+ %1:_(s64) = G_LOAD %0 :: (load (s64), align 8, addrspace 1)
+ %2:_(s64) = G_SEXT_INREG %1, 8
+ $vgpr0_vgpr1 = COPY %2
+...
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