[llvm] r362954 - [InstCombine] allow unordered preds when canonicalizing to fabs()

[Sanjay Patel via llvm-commits]

Author: spatel
Date: Mon Jun 10 08:39:00 2019
New Revision: 362954

URL: http://llvm.org/viewvc/llvm-project?rev=362954&view=rev
Log:
[InstCombine] allow unordered preds when canonicalizing to fabs()

We have a known-never-nan value via 'nnan', so an unordered predicate
is the same as its ordered sibling.

Similar to:
rL362937

Modified:
    llvm/trunk/lib/Transforms/InstCombine/InstCombineSelect.cpp
    llvm/trunk/test/Transforms/InstCombine/fabs.ll

Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineSelect.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineSelect.cpp?rev=362954&r1=362953&r2=362954&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineSelect.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineSelect.cpp Mon Jun 10 08:39:00 2019
@@ -1879,7 +1879,7 @@ Instruction *InstCombiner::visitSelectIn
   if (match(CondVal, m_FCmp(Pred, m_Specific(FalseVal), m_AnyZeroFP())) &&
       match(TrueVal, m_FSub(m_PosZeroFP(), m_Specific(FalseVal))) &&
       match(TrueVal, m_Instruction(FSub)) && FSub->hasNoNaNs() &&
-      Pred == FCmpInst::FCMP_OLE) {
+      (Pred == FCmpInst::FCMP_OLE || Pred == FCmpInst::FCMP_ULE)) {
     Value *Fabs = Builder.CreateUnaryIntrinsic(Intrinsic::fabs, FalseVal, FSub);
     return replaceInstUsesWith(SI, Fabs);
   }
@@ -1887,7 +1887,7 @@ Instruction *InstCombiner::visitSelectIn
   if (match(CondVal, m_FCmp(Pred, m_Specific(TrueVal), m_AnyZeroFP())) &&
       match(FalseVal, m_FSub(m_PosZeroFP(), m_Specific(TrueVal))) &&
       match(FalseVal, m_Instruction(FSub)) && FSub->hasNoNaNs() &&
-      Pred == FCmpInst::FCMP_OGT) {
+      (Pred == FCmpInst::FCMP_OGT || Pred == FCmpInst::FCMP_UGT)) {
     Value *Fabs = Builder.CreateUnaryIntrinsic(Intrinsic::fabs, TrueVal, FSub);
     return replaceInstUsesWith(SI, Fabs);
   }

Modified: llvm/trunk/test/Transforms/InstCombine/fabs.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/fabs.ll?rev=362954&r1=362953&r2=362954&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/fabs.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/fabs.ll Mon Jun 10 08:39:00 2019
@@ -279,10 +279,8 @@ define double @select_fcmp_nnan_ole_zero
 
 define double @select_fcmp_nnan_ule_zero(double %x) {
 ; CHECK-LABEL: @select_fcmp_nnan_ule_zero(
-; CHECK-NEXT:    [[LEZERO:%.*]] = fcmp ule double [[X:%.*]], 0.000000e+00
-; CHECK-NEXT:    [[NEGX:%.*]] = fsub nnan double 0.000000e+00, [[X]]
-; CHECK-NEXT:    [[FABS:%.*]] = select i1 [[LEZERO]], double [[NEGX]], double [[X]]
-; CHECK-NEXT:    ret double [[FABS]]
+; CHECK-NEXT:    [[TMP1:%.*]] = call nnan double @llvm.fabs.f64(double [[X:%.*]])
+; CHECK-NEXT:    ret double [[TMP1]]
 ;
   %lezero = fcmp ule double %x, 0.0
   %negx = fsub nnan double 0.0, %x
@@ -348,10 +346,8 @@ define half @select_fcmp_nnan_ogt_negzer
 
 define half @select_fcmp_nnan_ugt_negzero(half %x) {
 ; CHECK-LABEL: @select_fcmp_nnan_ugt_negzero(
-; CHECK-NEXT:    [[GTZERO:%.*]] = fcmp ugt half [[X:%.*]], 0xH0000
-; CHECK-NEXT:    [[NEGX:%.*]] = fsub nnan half 0xH0000, [[X]]
-; CHECK-NEXT:    [[FABS:%.*]] = select i1 [[GTZERO]], half [[X]], half [[NEGX]]
-; CHECK-NEXT:    ret half [[FABS]]
+; CHECK-NEXT:    [[TMP1:%.*]] = call nnan half @llvm.fabs.f16(half [[X:%.*]])
+; CHECK-NEXT:    ret half [[TMP1]]
 ;
   %gtzero = fcmp ugt half %x, -0.0
   %negx = fsub nnan half 0.0, %x