6b0ff0969d
This is a reoccuring pattern, we can consolidate three copies into one. The main motivation is to reduce usages of isMallocLike. The original commit (which was quickly reverted) didn't account for the allocation function could be an invoke, test coverage for that case added in this commit.
50 lines
1.3 KiB
LLVM
50 lines
1.3 KiB
LLVM
; RUN: opt -S -basic-aa -gvn < %s | FileCheck %s
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; RUN: opt -S -basic-aa -gvn -disable-simplify-libcalls < %s | FileCheck %s -check-prefix=CHECK_NO_LIBCALLS
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; Check that loads from calloc are recognized as being zero.
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target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
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; Function Attrs: nounwind uwtable
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define i32 @test1() {
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%1 = tail call noalias i8* @calloc(i64 1, i64 4)
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%2 = bitcast i8* %1 to i32*
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; This load is trivially constant zero
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%3 = load i32, i32* %2, align 4
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ret i32 %3
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; CHECK-LABEL: @test1(
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; CHECK-NOT: %3 = load i32, i32* %2, align 4
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; CHECK: ret i32 0
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; CHECK_NO_LIBCALLS-LABEL: @test1(
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; CHECK_NO_LIBCALLS: load
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; CHECK_NO_LIBCALLS: ret i32 %
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}
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define i32 @as_invoke(i1 %c) personality i32 (...)* undef {
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bb3:
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%mem = invoke noalias i8* @calloc(i64 1, i64 4)
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to label %bb4 unwind label %bb1
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bb1:
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%lp = landingpad { i8*, i32 } cleanup
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ret i32 0
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bb4:
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%mem.i32 = bitcast i8* %mem to i32*
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; This load is trivially constant zero
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%res = load i32, i32* %mem.i32, align 4
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ret i32 %res
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; CHECK-LABEL: @as_invoke(
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; CHECK-NOT: %3 = load i32, i32* %2, align 4
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; CHECK: ret i32 0
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; CHECK_NO_LIBCALLS-LABEL: @as_invoke(
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; CHECK_NO_LIBCALLS: load
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; CHECK_NO_LIBCALLS: ret i32 %
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}
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declare noalias i8* @calloc(i64, i64)
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