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[StatepointLowering] Use Constant instead of TargetConstant for undef value #81635

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Merged
merged 2 commits into from
Feb 13, 2024
Merged

[StatepointLowering] Use Constant instead of TargetConstant for undef value #81635

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ee3e832
[StatepointLowering] Use Constant instead of TargetConstant for undef…
danilaml Feb 13, 2024
d1112e1
Update llvm/test/CodeGen/X86/statepoint-relocate-undef.ll
danilaml Feb 13, 2024
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2 changes: 1 addition & 1 deletion llvm/lib/CodeGen/SelectionDAG/StatepointLowering.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1287,7 +1287,7 @@ void SelectionDAGBuilder::visitGCRelocate(const GCRelocateInst &Relocate) {
if (SD.isUndef() && SD.getValueType().getSizeInBits() <= 64) {
// Lowering relocate(undef) as arbitrary constant. Current constant value
// is chosen such that it's unlikely to be a valid pointer.
setValue(&Relocate, DAG.getTargetConstant(0xFEFEFEFE, SDLoc(SD), MVT::i64));
setValue(&Relocate, DAG.getConstant(0xFEFEFEFE, SDLoc(SD), MVT::i64));
return;
}

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32 changes: 32 additions & 0 deletions llvm/test/CodeGen/X86/statepoint-relocate-undef.ll
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@@ -0,0 +1,32 @@
; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
; RUN: llc -verify-machineinstrs < %s | FileCheck %s

target datalayout = "e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-pc-linux-gnu"

declare void @use(...)
declare void @f()
declare token @llvm.experimental.gc.statepoint.p0(i64, i32, ptr, i32, i32, ...)
declare ptr addrspace(1) @llvm.experimental.gc.relocate.p1(token, i32, i32)

;; Check that llvm doesn't crash if relocate with undef base/derived ptr survives until isel
define void @test_gcrelocate_undef(ptr addrspace(1) %ptr) gc "statepoint-example" {
; CHECK-LABEL: test_gcrelocate_undef:
; CHECK: # %bb.0:
; CHECK-NEXT: pushq %rax
; CHECK-NEXT: .cfi_def_cfa_offset 16
; CHECK-NEXT: movq %rdi, (%rsp)
; CHECK-NEXT: callq f@PLT
; CHECK-NEXT: .Ltmp0:
; CHECK-NEXT: movl $4278124286, %edi # imm = 0xFEFEFEFE
; CHECK-NEXT: xorl %eax, %eax
; CHECK-NEXT: callq use@PLT
; CHECK-NEXT: popq %rax
; CHECK-NEXT: .cfi_def_cfa_offset 8
; CHECK-NEXT: retq
%tok = tail call token (i64, i32, ptr, i32, i32, ...)
@llvm.experimental.gc.statepoint.p0(i64 0, i32 0, ptr elementtype(void ()) @f, i32 0, i32 0, i32 0, i32 0) ["gc-live" (ptr addrspace(1) %ptr, ptr addrspace(1) undef), "deopt" (ptr addrspace(1) %ptr, i32 undef)]
%a = call ptr addrspace(1) @llvm.experimental.gc.relocate.p1(token %tok, i32 0, i32 1)
call void (...) @use(ptr addrspace(1) %a)
ret void
}