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[ConstantFold] Check uniform value in ConstantFoldLoadFromConst() 

This case is automatically handled if ConstantFoldLoadFromConstPtr()
is used. Make sure that ConstantFoldLoadFromConst() also handles it.
This commit is contained in:
Nikita Popov 2022-01-13 14:37:20 +01:00
parent 235886e174
commit aba7c3c033
2 changed files with 25 additions and 2 deletions
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7
llvm/lib/Analysis/ConstantFolding.cpp
View File

@ -671,9 +671,12 @@ Constant *llvm::ConstantFoldLoadFromConst(Constant *C, Type *Ty,
// Try hard to fold loads from bitcasted strange and non-type-safe things.
if (Offset.getMinSignedBits() <= 64)
return FoldReinterpretLoadFromConst(C, Ty, Offset.getSExtValue(), DL);
if (Constant *Result =
FoldReinterpretLoadFromConst(C, Ty, Offset.getSExtValue(), DL))
return Result;
return nullptr;
// Try an offset-independent fold of a uniform value.
return ConstantFoldLoadFromUniformValue(C, Ty);
}
Constant *llvm::ConstantFoldLoadFromConst(Constant *C, Type *Ty,

20
llvm/test/Transforms/GlobalOpt/evaluate-load-uniform.ll Normal file
View File

@ -0,0 +1,20 @@
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --check-globals
; RUN: opt -S -globalopt < %s | FileCheck %s
; Make sure that the load from uniform value @g1 succeeds during evaluation.
@g1 = global [2 x i64*] zeroinitializer
@g2 = global i64* inttoptr(i64 1 to i64*)
@llvm.global_ctors = appending global [1 x { i32, void ()*, i8* }] [{ i32, void ()*, i8* } { i32 65535, void ()* @ctor, i8* null }]
;.
; CHECK: @[[G1:[a-zA-Z0-9_$"\\.-]+]] = local_unnamed_addr global [2 x i64*] zeroinitializer
; CHECK: @[[G2:[a-zA-Z0-9_$"\\.-]+]] = local_unnamed_addr global i64* null
; CHECK: @[[LLVM_GLOBAL_CTORS:[a-zA-Z0-9_$"\\.-]+]] = appending global [0 x { i32, void ()*, i8* }] zeroinitializer
;.
define internal void @ctor() {
%v = load i64*, i64** getelementptr ([2 x i64*], [2 x i64*]* @g1, i64 0, i64 1)
store i64* %v, i64** @g2
ret void
}