add-sub-nsw-nuw.ll
704 Bytes
; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
; RUN: llc -mtriple=i386-apple-darwin < %s | FileCheck %s
; PR30841: https://llvm.org/bugs/show_bug.cgi?id=30841
; Demanded bits analysis must disable nsw/nuw when it makes a
; simplification to add/sub such as in this case.
define i8 @PR30841(i64 %argc) {
; CHECK-LABEL: PR30841:
; CHECK: ## %bb.0: ## %entry
; CHECK-NEXT: movl {{[0-9]+}}(%esp), %eax
; CHECK-NEXT: negb %al
; CHECK-NEXT: ## kill: def $al killed $al killed $eax
; CHECK-NEXT: retl
entry:
%or = or i64 %argc, -4294967296
br label %end
end:
%neg = sub nuw nsw i64 -4294967296, %argc
%trunc = trunc i64 %neg to i8
ret i8 %trunc
}