43 lines
1.3 KiB
LLVM
43 lines
1.3 KiB
LLVM
; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
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; RUN: llc < %s -O2 -mtriple=x86_64-unknown-unknown | FileCheck %s
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; Checks that a zeroing mov is inserted for the trunc/zext pair even when
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; the source of the zext is an AssertZext node
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; PR28540
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define i64 @foo() {
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; CHECK-LABEL: foo:
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; CHECK: # %bb.0:
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; CHECK-NEXT: movq $-1, %rax
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; CHECK-NEXT: retq
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ret i64 -1
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}
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define i64 @main() {
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; CHECK-LABEL: main:
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; CHECK: # %bb.0:
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; CHECK-NEXT: pushq %rax
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; CHECK-NEXT: .cfi_def_cfa_offset 16
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; CHECK-NEXT: callq foo@PLT
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; CHECK-NEXT: movabsq $-4294967041, %rcx # imm = 0xFFFFFFFF000000FF
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; CHECK-NEXT: andq %rax, %rcx
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; CHECK-NEXT: movl %ecx, %ecx
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; CHECK-NEXT: leaq (,%rcx,8), %rax
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; CHECK-NEXT: subq %rcx, %rax
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; CHECK-NEXT: shrq $32, %rax
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; CHECK-NEXT: popq %rcx
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; CHECK-NEXT: .cfi_def_cfa_offset 8
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; CHECK-NEXT: retq
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%b = call i64 @foo()
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%or = and i64 %b, 18446744069414584575 ; this is 0xffffffff000000ff
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%trunc = trunc i64 %or to i32
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br label %l
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l:
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%ext = zext i32 %trunc to i64
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%mul = mul i64 %ext, 7
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br label %m
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m: ; keeps dag combine from seeing the multiply and the shift together
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%shr = lshr i64 %mul, 32
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trunc i64 %or to i32 ; keeps the and alive so it doesn't simplify
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ret i64 %shr
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}
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