[X86][GlobalISel] Fix referencing nonexistent operand in G_ICMP #86221
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@llvm/pr-subscribers-llvm-globalisel @llvm/pr-subscribers-backend-x86 Author: Evgenii Kudriashov (e-kud) ChangesFixes #86203 Full diff: https://github.com/llvm/llvm-project/pull/86221.diff 2 Files Affected:
diff --git a/llvm/lib/Target/X86/GISel/X86LegalizerInfo.cpp b/llvm/lib/Target/X86/GISel/X86LegalizerInfo.cpp
index 06389842ebb1ed..07041cc5b0491c 100644
--- a/llvm/lib/Target/X86/GISel/X86LegalizerInfo.cpp
+++ b/llvm/lib/Target/X86/GISel/X86LegalizerInfo.cpp
@@ -259,8 +259,7 @@ X86LegalizerInfo::X86LegalizerInfo(const X86Subtarget &STI,
getActionDefinitionsBuilder(G_ICMP)
.legalForCartesianProduct({s8}, Is64Bit ? IntTypes64 : IntTypes32)
.clampScalar(0, s8, s8)
- .clampScalar(1, s8, sMaxScalar)
- .scalarSameSizeAs(2, 1);
+ .clampScalar(1, s8, sMaxScalar);
// bswap
getActionDefinitionsBuilder(G_BSWAP)
diff --git a/llvm/test/CodeGen/X86/GlobalISel/legalize-icmp-vec.mir b/llvm/test/CodeGen/X86/GlobalISel/legalize-icmp-vec.mir
new file mode 100644
index 00000000000000..e18527ec681fe4
--- /dev/null
+++ b/llvm/test/CodeGen/X86/GlobalISel/legalize-icmp-vec.mir
@@ -0,0 +1,24 @@
+# RUN: llc -mtriple=x86_64-linux-gnu -run-pass=legalizer -global-isel-abort=2 -pass-remarks-missed='gisel*' %s -o - 2>%t | FileCheck %s
+# RUN: FileCheck -check-prefix=NOTLEGAL %s < %t
+
+# NOTLEGAL: remark: <unknown>:0:0: unable to legalize instruction: %2:_(<4 x s1>) = G_ICMP intpred(sle), %0:_(<4 x s64>), %1:_ (in function: test_icmp_v4i64)
+
+---
+name: test_icmp_v4i64
+tracksRegLiveness: true
+body: |
+ bb.1:
+ ; CHECK-LABEL: name: test_icmp_v4i64
+ ; CHECK: [[DEF:%[0-9]+]]:_(<4 x s64>) = G_IMPLICIT_DEF
+ ; CHECK-NEXT: [[DEF1:%[0-9]+]]:_(<4 x s64>) = G_IMPLICIT_DEF
+ ; CHECK-NEXT: [[ICMP:%[0-9]+]]:_(<4 x s1>) = G_ICMP intpred(sle), [[DEF]](<4 x s64>), [[DEF1]]
+ ; CHECK-NEXT: [[ANYEXT:%[0-9]+]]:_(<4 x s32>) = G_ANYEXT [[ICMP]](<4 x s1>)
+ ; CHECK-NEXT: $xmm0 = COPY [[ANYEXT]](<4 x s32>)
+ ; CHECK-NEXT: RET 0, implicit $xmm0
+ %0:_(<4 x s64>) = G_IMPLICIT_DEF
+ %1:_(<4 x s64>) = G_IMPLICIT_DEF
+ %3:_(<4 x s1>) = G_ICMP intpred(sle), %0(<4 x s64>), %1
+ %4:_(<4 x s32>) = G_ANYEXT %3(<4 x s1>)
+ $xmm0 = COPY %4(<4 x s32>)
+ RET 0, implicit $xmm0
+...
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| # RUN: llc -mtriple=x86_64-linux-gnu -run-pass=legalizer -global-isel-abort=2 -pass-remarks-missed='gisel*' %s -o - 2>%t | FileCheck %s | ||
| # RUN: FileCheck -check-prefix=ILLEGAL %s < %t | ||
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| # ILLEGAL: remark: <unknown>:0:0: unable to legalize instruction: %2:_(<4 x s1>) = G_ICMP intpred(sle), %0:_(<4 x s64>), %1:_ (in function: test_icmp_v4i64) |
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Is this patch only to fix the first crash reported in #86203?
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Please can you add a reference to PR86203?
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@phoebewang it's not a crash, actually. The crash happens if we use only -global-isel. This option forces llc to use only GlobalISel. The correct way is to use -fglobal-isel with clang or -global-isel -global-isel-abort=2 with llc. It allows to fallback to SelectionDAG if something is unsupported in GlobalISel. Without this fix we hit the assert and are not able to fallback to SelectionDAG.
@RKSimon done.
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/cherry-pick fb39456 |
Error: Command failed due to missing milestone. |
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@AtariDreams GlobalISel is still very much in development for X86. Why do you think this needs to be backported? |
Fixes #86203