[llvm] r346324 - [InstCombine] add folds for fcmp Pred fabs(X), 0.0

[Sanjay Patel via llvm-commits]

Author: spatel
Date: Wed Nov  7 07:33:03 2018
New Revision: 346324

URL: http://llvm.org/viewvc/llvm-project?rev=346324&view=rev
Log:
[InstCombine] add folds for fcmp Pred fabs(X), 0.0

Similar to rL346321, we had folds for the ordered
versions of these compares already, so add the
unordered siblings for completeness.

Modified:
    llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp
    llvm/trunk/test/Transforms/InstCombine/fcmp.ll

Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp?rev=346324&r1=346323&r2=346324&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp Wed Nov  7 07:33:03 2018
@@ -5302,10 +5302,18 @@ static Instruction *foldFabsWithFcmpZero
     // fabs(X) > 0.0 --> X != 0.0
     return new FCmpInst(FCmpInst::FCMP_ONE, X, I.getOperand(1));
 
+  case FCmpInst::FCMP_UGT:
+    // fabs(X) u> 0.0 --> X u!= 0.0
+    return new FCmpInst(FCmpInst::FCMP_UNE, X, I.getOperand(1));
+
   case FCmpInst::FCMP_OLE:
     // fabs(X) <= 0.0 --> X == 0.0
     return new FCmpInst(FCmpInst::FCMP_OEQ, X, I.getOperand(1));
 
+  case FCmpInst::FCMP_ULE:
+    // fabs(X) u<= 0.0 --> X u== 0.0
+    return new FCmpInst(FCmpInst::FCMP_UEQ, X, I.getOperand(1));
+
   case FCmpInst::FCMP_OGE:
     // fabs(X) >= 0.0 --> !isnan(X)
     assert(!I.hasNoNaNs() && "fcmp should have simplified");

Modified: llvm/trunk/test/Transforms/InstCombine/fcmp.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/fcmp.ll?rev=346324&r1=346323&r2=346324&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/fcmp.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/fcmp.ll Wed Nov  7 07:33:03 2018
@@ -199,8 +199,7 @@ define <2 x i1> @fabs_ole(<2 x float> %a
 
 define <2 x i1> @fabs_ule(<2 x float> %a) {
 ; CHECK-LABEL: @fabs_ule(
-; CHECK-NEXT:    [[CALL:%.*]] = call <2 x float> @llvm.fabs.v2f32(<2 x float> [[A:%.*]])
-; CHECK-NEXT:    [[CMP:%.*]] = fcmp ninf arcp ule <2 x float> [[CALL]], zeroinitializer
+; CHECK-NEXT:    [[CMP:%.*]] = fcmp ueq <2 x float> [[A:%.*]], zeroinitializer
 ; CHECK-NEXT:    ret <2 x i1> [[CMP]]
 ;
   %call = call <2 x float> @llvm.fabs.v2f32(<2 x float> %a)
@@ -220,8 +219,7 @@ define i1 @fabs_ogt(double %a) {
 
 define i1 @fabs_ugt(double %a) {
 ; CHECK-LABEL: @fabs_ugt(
-; CHECK-NEXT:    [[CALL:%.*]] = call double @llvm.fabs.f64(double [[A:%.*]])
-; CHECK-NEXT:    [[CMP:%.*]] = fcmp reassoc ninf ugt double [[CALL]], 0.000000e+00
+; CHECK-NEXT:    [[CMP:%.*]] = fcmp une double [[A:%.*]], 0.000000e+00
 ; CHECK-NEXT:    ret i1 [[CMP]]
 ;
   %call = call double @llvm.fabs.f64(double %a)