[llvm] r363945 - [InstCombine] add commuted variants for power-of-2 checks; NFC

[Sanjay Patel via llvm-commits]

Author: spatel
Date: Thu Jun 20 09:27:23 2019
New Revision: 363945

URL: http://llvm.org/viewvc/llvm-project?rev=363945&view=rev
Log:
[InstCombine] add commuted variants for power-of-2 checks; NFC

Modified:
    llvm/trunk/test/Transforms/InstCombine/ispow2.ll

Modified: llvm/trunk/test/Transforms/InstCombine/ispow2.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/ispow2.ll?rev=363945&r1=363944&r2=363945&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/ispow2.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/ispow2.ll Thu Jun 20 09:27:23 2019
@@ -105,6 +105,53 @@ define <2 x i1> @isnot_pow2or0_decrement
   ret <2 x i1> %cmp
 }
 
+define i1 @is_pow2or0_negate_op_commute1(i32 %p) {
+; CHECK-LABEL: @is_pow2or0_negate_op_commute1(
+; CHECK-NEXT:    [[X:%.*]] = srem i32 42, [[P:%.*]]
+; CHECK-NEXT:    [[NEG:%.*]] = sub nsw i32 0, [[X]]
+; CHECK-NEXT:    [[AND:%.*]] = and i32 [[X]], [[NEG]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i32 [[AND]], [[X]]
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %x = srem i32 42, %p ; thwart complexity-based canonicalization
+  %neg = sub i32 0, %x
+  %and = and i32 %x, %neg
+  %cmp = icmp eq i32 %and, %x
+  ret i1 %cmp
+}
+
+; x can't be <= complexity of the 'neg' but >= complexity of the 'and'.
+
+define i1 @isnot_pow2or0_negate_op_commute2(i32 %p) {
+; CHECK-LABEL: @isnot_pow2or0_negate_op_commute2(
+; CHECK-NEXT:    [[X:%.*]] = urem i32 42, [[P:%.*]]
+; CHECK-NEXT:    [[NEG:%.*]] = sub nsw i32 0, [[X]]
+; CHECK-NEXT:    [[AND:%.*]] = and i32 [[X]], [[NEG]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ne i32 [[X]], [[AND]]
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %x = urem i32 42, %p ; thwart complexity-based canonicalization
+  %neg = sub i32 0, %x
+  %and = and i32 %neg, %x
+  %cmp = icmp ne i32 %x, %and
+  ret i1 %cmp
+}
+
+define i1 @isnot_pow2or0_negate_op_commute3(i32 %p) {
+; CHECK-LABEL: @isnot_pow2or0_negate_op_commute3(
+; CHECK-NEXT:    [[X:%.*]] = urem i32 42, [[P:%.*]]
+; CHECK-NEXT:    [[NEG:%.*]] = sub nsw i32 0, [[X]]
+; CHECK-NEXT:    [[AND:%.*]] = and i32 [[X]], [[NEG]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ne i32 [[X]], [[AND]]
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %x = urem i32 42, %p ; thwart complexity-based canonicalization
+  %neg = sub i32 0, %x
+  %and = and i32 %x, %neg
+  %cmp = icmp ne i32 %x, %and
+  ret i1 %cmp
+}
+
 declare void @use(i32)
 
 define i1 @is_pow2or0_negate_op_extra_use1(i32 %x) {