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