[InstCombine] Test cases added for pattern "(~A & B) ^ A -> (A | B)"

[spatel]

Summary

Test cases are added for pattern "(~A & B) ^ A -> (A | B)".

And Fix for these pattern is https://reviews.llvm.org/D86395.

[Jac1494]

Updated full patch to solve "content not available" error.

[spatel]

llvm/test/Transforms/InstCombine/xor.ll

1182

I don't understand what this patch is proposing. Why is the output changing for an unmodified test?

[RKSimon]

@Jac1494 Please can you rebase this patch against trunk - from the CHECK changes in existing tests it looks like you have some local changes as well.

[spatel]

Commandeering to close the review. I made test changes with rG77fb8cbd60cf that should provide the coverage I requested.

llvm/test/Transforms/InstCombine/xor.ll

 ; CHECK-NEXT:    [[R:%.*]] = xor i8 [[A]], -2
 ; CHECK-NEXT:    ret i8 [[R]]
 ;
   %a = ashr i8 %x, 5
   %r = xor i8 %a, -2
   ret i8 %r
 }
 
-; (~A & B) ^ A  -->   (A | B)
+; (~A & B) ^ A -> (A | B)
 ; The division ops are here to thwart complexity-based canonicalization: all ops are binops.
 
 define i32 @test52(i32 %p1, i32 %p2) {
 ; CHECK-LABEL: @test52(
 ; CHECK-NEXT:    [[A:%.*]] = udiv i32 42, [[P1:%.*]]
 ; CHECK-NEXT:    [[B:%.*]] = udiv i32 42, [[P2:%.*]]
-; CHECK-NEXT:    [[O:%.*]] = xor i32 [[A]], -1
-; CHECK-NEXT:    [[R:%.*]] = and i32 [[B]], [[O]]
-; CHECK-NEXT:    [[Z:%.*]] = xor i32 [[R]], [[A]]
+; CHECK-NEXT:    [[Z:%.*]] = or i32 [[A]], [[B]]
 ; CHECK-NEXT:    ret i32 [[Z]]
 ;
   %a = udiv i32 42, %p1
   %b = udiv i32 42, %p2
   %o = xor i32 %a, -1
   %r = and i32 %o, %b
   %z = xor i32 %r, %a
   ret i32 %z
 }
 
-; (~B & A) ^ B  -->   (A | B)
+; (B & ~A) ^ A -> (A | B)
 ; The division ops are here to thwart complexity-based canonicalization: all ops are binops.
 
 define i32 @test53(i32 %p1, i32 %p2) {
 ; CHECK-LABEL: @test53(
 ; CHECK-NEXT:    [[A:%.*]] = udiv i32 42, [[P1:%.*]]
 ; CHECK-NEXT:    [[B:%.*]] = udiv i32 42, [[P2:%.*]]
-; CHECK-NEXT:    [[O:%.*]] = xor i32 [[B]], -1
-; CHECK-NEXT:    [[R:%.*]] = and i32 [[A]], [[O]]
-; CHECK-NEXT:    [[Z:%.*]] = xor i32 [[R]], [[B]]
+; CHECK-NEXT:    [[Z:%.*]] = or i32 [[A]], [[B]]
 ; CHECK-NEXT:    ret i32 [[Z]]
 ;
   %a = udiv i32 42, %p1
   %b = udiv i32 42, %p2
-  %o = xor i32 %b, -1
-  %r = and i32 %o, %a
-  %z = xor i32 %r, %b
+  %o = xor i32 %a, -1
+  %r = and i32 %o, %b
+  %z = xor i32 %r, %a
   ret i32 %z
 }
 
+; A ^ (~A & B) -> (A | B)
+; The division ops are here to thwart complexity-based canonicalization: all ops are binops.
+
 define i32 @test54(i32 %p1, i32 %p2) {
 ; CHECK-LABEL: @test54(
 ; CHECK-NEXT:    [[A:%.*]] = udiv i32 42, [[P1:%.*]]
 ; CHECK-NEXT:    [[B:%.*]] = udiv i32 42, [[P2:%.*]]
-; CHECK-NEXT:    [[O:%.*]] = xor i32 [[A]], -1
-; CHECK-NEXT:    [[R:%.*]] = and i32 [[B]], [[O]]
-; CHECK-NEXT:    [[Z:%.*]] = xor i32 [[R]], [[A]]
+; CHECK-NEXT:    [[Z:%.*]] = or i32 [[A]], [[B]]
 ; CHECK-NEXT:    ret i32 [[Z]]
 ;
   %a = udiv i32 42, %p1
   %b = udiv i32 42, %p2
   %o = xor i32 %a, -1
-  %r = and i32 %b, %o
+  %r = and i32 %o, %b
   %z = xor i32 %r, %a
   ret i32 %z
 }
 
+; A ^ (B & ~A) -> (A | B)
+; The division ops are here to thwart complexity-based canonicalization: all ops are binops.
+
 define i32 @test55(i32 %p1, i32 %p2) {
 ; CHECK-LABEL: @test55(
 ; CHECK-NEXT:    [[A:%.*]] = udiv i32 42, [[P1:%.*]]
 ; CHECK-NEXT:    [[B:%.*]] = udiv i32 42, [[P2:%.*]]
-; CHECK-NEXT:    [[O:%.*]] = xor i32 [[A]], -1
-; CHECK-NEXT:    [[R:%.*]] = and i32 [[B]], [[O]]
-; CHECK-NEXT:    [[Z:%.*]] = xor i32 [[A]], [[R]]
+; CHECK-NEXT:    [[Z:%.*]] = or i32 [[A]], [[B]]
 ; CHECK-NEXT:    ret i32 [[Z]]
 ;
   %a = udiv i32 42, %p1
   %b = udiv i32 42, %p2
   %o = xor i32 %a, -1
   %r = and i32 %o, %b
-  %z = xor i32 %a, %r
+  %z = xor i32 %r, %a
   ret i32 %z
 }