maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

[InstCombine] add test for 'not' vs 'xor'; NFC

This commit is contained in:
Sanjay Patel 2020-08-12 15:07:45 -04:00
parent 5c1fe4e20f
commit 0a1514d7ca
1 changed files with 16 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
llvm/test/Transforms/InstCombine/xor.ll
View File

@ -994,3 +994,19 @@ define i4 @or_or_xor_use2(i4 %x, i4 %y, i4 %z, i4* %p) {
%r = xor i4 %o1, %o2
ret i4 %r
}
; PR32706 - https://bugs.llvm.org/show_bug.cgi?id=32706
; TODO: Pin an xor constant operand to -1 if possible because 'not' is better for SCEV and codegen.
define i32 @not_is_canonical(i32 %x, i32 %y) {
; CHECK-LABEL: @not_is_canonical(
; CHECK-NEXT: [[SUB:%.*]] = xor i32 [[X:%.*]], 1073741823
; CHECK-NEXT: [[ADD:%.*]] = add i32 [[SUB]], [[Y:%.*]]
; CHECK-NEXT: [[MUL:%.*]] = shl i32 [[ADD]], 2
; CHECK-NEXT: ret i32 [[MUL]]
;
%sub = xor i32 %x, 1073741823
%add = add i32 %sub, %y
%mul = shl i32 %add, 2
ret i32 %mul
}