Index: llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
===================================================================
--- llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
+++ llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
@@ -2942,7 +2942,19 @@
     Value *Fabs = Builder.CreateUnaryIntrinsic(Intrinsic::fabs, TrueVal, &SI);
     return replaceInstUsesWith(SI, Fabs);
   }
-  // With nnan and nsz:
+  // (X < +/-0.0) ? X : (0.0 - X) --> (0.0 - fabs(X))
+  // With nsz:
+  // (X < +/-0.0) ? X : -X --> -fabs(X)
+  if (match(CondVal, m_FCmp(Pred, m_Specific(TrueVal), m_AnyZeroFP())) &&
+      (match(FalseVal, m_FSub(m_PosZeroFP(), m_Specific(TrueVal))) ||
+       (match(FalseVal, m_FNeg(m_Specific(TrueVal))) &&
+        cast<Instruction>(FalseVal)->hasNoSignedZeros())) &&
+      (Pred == FCmpInst::FCMP_OLT || Pred == FCmpInst::FCMP_ULT)) {
+    Value *Fabs = Builder.CreateUnaryIntrinsic(Intrinsic::fabs, TrueVal, &SI);
+    return BinaryOperator::CreateFSubFMF(ConstantFP::get(Fabs->getType(), 0.0),
+                                         Fabs, cast<Instruction>(FalseVal));
+  }
+  // With nsz:
   // (X <  +/-0.0) ? -X : X --> fabs(X)
   // (X <= +/-0.0) ? -X : X --> fabs(X)
   if (match(CondVal, m_FCmp(Pred, m_Specific(FalseVal), m_AnyZeroFP())) &&
@@ -2952,7 +2964,7 @@
     Value *Fabs = Builder.CreateUnaryIntrinsic(Intrinsic::fabs, FalseVal, &SI);
     return replaceInstUsesWith(SI, Fabs);
   }
-  // With nnan and nsz:
+  // With nsz:
   // (X >  +/-0.0) ? X : -X --> fabs(X)
   // (X >= +/-0.0) ? X : -X --> fabs(X)
   if (match(CondVal, m_FCmp(Pred, m_Specific(TrueVal), m_AnyZeroFP())) &&
@@ -2962,6 +2974,26 @@
     Value *Fabs = Builder.CreateUnaryIntrinsic(Intrinsic::fabs, TrueVal, &SI);
     return replaceInstUsesWith(SI, Fabs);
   }
+  // With nsz:
+  // (X <  +/-0.0) ? X : -X --> -fabs(X)
+  // (X <= +/-0.0) ? X : -X --> -fabs(X)
+  if (match(CondVal, m_FCmp(Pred, m_Specific(TrueVal), m_AnyZeroFP())) &&
+      match(FalseVal, m_FNeg(m_Specific(TrueVal))) && SI.hasNoSignedZeros() &&
+      (Pred == FCmpInst::FCMP_OLT || Pred == FCmpInst::FCMP_OLE ||
+       Pred == FCmpInst::FCMP_ULT || Pred == FCmpInst::FCMP_ULE)) {
+    Value *Fabs = Builder.CreateUnaryIntrinsic(Intrinsic::fabs, TrueVal, &SI);
+    return UnaryOperator::CreateFNegFMF(Fabs, cast<Instruction>(FalseVal));
+  }
+  // With nsz:
+  // (X >  +/-0.0) ? -X : X --> -fabs(X)
+  // (X >= +/-0.0) ? -X : X --> -fabs(X)
+  if (match(CondVal, m_FCmp(Pred, m_Specific(FalseVal), m_AnyZeroFP())) &&
+      match(TrueVal, m_FNeg(m_Specific(FalseVal))) && SI.hasNoSignedZeros() &&
+      (Pred == FCmpInst::FCMP_OGT || Pred == FCmpInst::FCMP_OGE ||
+       Pred == FCmpInst::FCMP_UGT || Pred == FCmpInst::FCMP_UGE)) {
+    Value *Fabs = Builder.CreateUnaryIntrinsic(Intrinsic::fabs, FalseVal, &SI);
+    return UnaryOperator::CreateFNegFMF(Fabs, cast<Instruction>(TrueVal));
+  }
 
   // See if we are selecting two values based on a comparison of the two values.
   if (ICmpInst *ICI = dyn_cast<ICmpInst>(CondVal))
Index: llvm/test/Transforms/InstCombine/fneg-fabs.ll
===================================================================
--- llvm/test/Transforms/InstCombine/fneg-fabs.ll
+++ llvm/test/Transforms/InstCombine/fneg-fabs.ll
@@ -20,9 +20,8 @@
 ; One test where the neg has fmfs.
 define double @select_nsz_nfabs_lt_fmfProp(double %x) {
 ; CHECK-LABEL: @select_nsz_nfabs_lt_fmfProp(
-; CHECK-NEXT:    [[CMP:%.*]] = fcmp olt double [[X:%.*]], 0.000000e+00
-; CHECK-NEXT:    [[NEGX:%.*]] = fneg fast double [[X]]
-; CHECK-NEXT:    [[SEL:%.*]] = select nsz i1 [[CMP]], double [[X]], double [[NEGX]]
+; CHECK-NEXT:    [[TMP1:%.*]] = call nsz double @llvm.fabs.f64(double [[X:%.*]])
+; CHECK-NEXT:    [[SEL:%.*]] = fneg fast double [[TMP1]]
 ; CHECK-NEXT:    ret double [[SEL]]
 ;
   %cmp = fcmp olt double %x, 0.000000e+00
@@ -34,9 +33,8 @@
 ; Tests with various predicate types.
 define double @select_nsz_nfabs_olt(double %x) {
 ; CHECK-LABEL: @select_nsz_nfabs_olt(
-; CHECK-NEXT:    [[CMP:%.*]] = fcmp olt double [[X:%.*]], 0.000000e+00
-; CHECK-NEXT:    [[NEGX:%.*]] = fneg double [[X]]
-; CHECK-NEXT:    [[SEL:%.*]] = select nsz i1 [[CMP]], double [[X]], double [[NEGX]]
+; CHECK-NEXT:    [[TMP1:%.*]] = call nsz double @llvm.fabs.f64(double [[X:%.*]])
+; CHECK-NEXT:    [[SEL:%.*]] = fneg double [[TMP1]]
 ; CHECK-NEXT:    ret double [[SEL]]
 ;
   %cmp = fcmp olt double %x, 0.000000e+00
@@ -47,9 +45,8 @@
 
 define double @select_nsz_nfabs_ult(double %x) {
 ; CHECK-LABEL: @select_nsz_nfabs_ult(
-; CHECK-NEXT:    [[CMP:%.*]] = fcmp ult double [[X:%.*]], 0.000000e+00
-; CHECK-NEXT:    [[NEGX:%.*]] = fneg double [[X]]
-; CHECK-NEXT:    [[SEL:%.*]] = select nsz i1 [[CMP]], double [[X]], double [[NEGX]]
+; CHECK-NEXT:    [[TMP1:%.*]] = call nsz double @llvm.fabs.f64(double [[X:%.*]])
+; CHECK-NEXT:    [[SEL:%.*]] = fneg double [[TMP1]]
 ; CHECK-NEXT:    ret double [[SEL]]
 ;
   %cmp = fcmp ult double %x, 0.000000e+00
@@ -60,9 +57,8 @@
 
 define double @select_nsz_nfabs_ole(double %x) {
 ; CHECK-LABEL: @select_nsz_nfabs_ole(
-; CHECK-NEXT:    [[CMP:%.*]] = fcmp ole double [[X:%.*]], 0.000000e+00
-; CHECK-NEXT:    [[NEGX:%.*]] = fneg double [[X]]
-; CHECK-NEXT:    [[SEL:%.*]] = select nsz i1 [[CMP]], double [[X]], double [[NEGX]]
+; CHECK-NEXT:    [[TMP1:%.*]] = call nsz double @llvm.fabs.f64(double [[X:%.*]])
+; CHECK-NEXT:    [[SEL:%.*]] = fneg double [[TMP1]]
 ; CHECK-NEXT:    ret double [[SEL]]
 ;
   %cmp = fcmp ole double %x, 0.000000e+00
@@ -73,9 +69,8 @@
 
 define double @select_nsz_nfabs_ule(double %x) {
 ; CHECK-LABEL: @select_nsz_nfabs_ule(
-; CHECK-NEXT:    [[CMP:%.*]] = fcmp ule double [[X:%.*]], 0.000000e+00
-; CHECK-NEXT:    [[NEGX:%.*]] = fneg double [[X]]
-; CHECK-NEXT:    [[SEL:%.*]] = select nsz i1 [[CMP]], double [[X]], double [[NEGX]]
+; CHECK-NEXT:    [[TMP1:%.*]] = call nsz double @llvm.fabs.f64(double [[X:%.*]])
+; CHECK-NEXT:    [[SEL:%.*]] = fneg double [[TMP1]]
 ; CHECK-NEXT:    ret double [[SEL]]
 ;
   %cmp = fcmp ule double %x, 0.000000e+00
@@ -103,9 +98,8 @@
 ; One test where the neg has fmfs.
 define double @select_nsz_nfabs_gt_fmfProp(double %x) {
 ; CHECK-LABEL: @select_nsz_nfabs_gt_fmfProp(
-; CHECK-NEXT:    [[CMP:%.*]] = fcmp ogt double [[X:%.*]], 0.000000e+00
-; CHECK-NEXT:    [[NEGX:%.*]] = fneg fast double [[X]]
-; CHECK-NEXT:    [[SEL:%.*]] = select nsz i1 [[CMP]], double [[NEGX]], double [[X]]
+; CHECK-NEXT:    [[TMP1:%.*]] = call nsz double @llvm.fabs.f64(double [[X:%.*]])
+; CHECK-NEXT:    [[SEL:%.*]] = fneg fast double [[TMP1]]
 ; CHECK-NEXT:    ret double [[SEL]]
 ;
   %cmp = fcmp ogt double %x, 0.000000e+00
@@ -117,9 +111,8 @@
 ; Tests with various predicate types.
 define double @select_nsz_nfabs_ogt(double %x) {
 ; CHECK-LABEL: @select_nsz_nfabs_ogt(
-; CHECK-NEXT:    [[CMP:%.*]] = fcmp ogt double [[X:%.*]], 0.000000e+00
-; CHECK-NEXT:    [[NEGX:%.*]] = fneg double [[X]]
-; CHECK-NEXT:    [[SEL:%.*]] = select nsz i1 [[CMP]], double [[NEGX]], double [[X]]
+; CHECK-NEXT:    [[TMP1:%.*]] = call nsz double @llvm.fabs.f64(double [[X:%.*]])
+; CHECK-NEXT:    [[SEL:%.*]] = fneg double [[TMP1]]
 ; CHECK-NEXT:    ret double [[SEL]]
 ;
   %cmp = fcmp ogt double %x, 0.000000e+00
@@ -130,9 +123,8 @@
 
 define double @select_nsz_nfabs_ugt(double %x) {
 ; CHECK-LABEL: @select_nsz_nfabs_ugt(
-; CHECK-NEXT:    [[CMP:%.*]] = fcmp ugt double [[X:%.*]], 0.000000e+00
-; CHECK-NEXT:    [[NEGX:%.*]] = fneg double [[X]]
-; CHECK-NEXT:    [[SEL:%.*]] = select nsz i1 [[CMP]], double [[NEGX]], double [[X]]
+; CHECK-NEXT:    [[TMP1:%.*]] = call nsz double @llvm.fabs.f64(double [[X:%.*]])
+; CHECK-NEXT:    [[SEL:%.*]] = fneg double [[TMP1]]
 ; CHECK-NEXT:    ret double [[SEL]]
 ;
   %cmp = fcmp ugt double %x, 0.000000e+00
@@ -143,9 +135,8 @@
 
 define double @select_nsz_nfabs_oge(double %x) {
 ; CHECK-LABEL: @select_nsz_nfabs_oge(
-; CHECK-NEXT:    [[CMP:%.*]] = fcmp oge double [[X:%.*]], 0.000000e+00
-; CHECK-NEXT:    [[NEGX:%.*]] = fneg double [[X]]
-; CHECK-NEXT:    [[SEL:%.*]] = select nsz i1 [[CMP]], double [[NEGX]], double [[X]]
+; CHECK-NEXT:    [[TMP1:%.*]] = call nsz double @llvm.fabs.f64(double [[X:%.*]])
+; CHECK-NEXT:    [[SEL:%.*]] = fneg double [[TMP1]]
 ; CHECK-NEXT:    ret double [[SEL]]
 ;
   %cmp = fcmp oge double %x, 0.000000e+00
@@ -156,9 +147,8 @@
 
 define double @select_nsz_nfabs_uge(double %x) {
 ; CHECK-LABEL: @select_nsz_nfabs_uge(
-; CHECK-NEXT:    [[CMP:%.*]] = fcmp uge double [[X:%.*]], 0.000000e+00
-; CHECK-NEXT:    [[NEGX:%.*]] = fneg double [[X]]
-; CHECK-NEXT:    [[SEL:%.*]] = select nsz i1 [[CMP]], double [[NEGX]], double [[X]]
+; CHECK-NEXT:    [[TMP1:%.*]] = call nsz double @llvm.fabs.f64(double [[X:%.*]])
+; CHECK-NEXT:    [[SEL:%.*]] = fneg double [[TMP1]]
 ; CHECK-NEXT:    ret double [[SEL]]
 ;
   %cmp = fcmp uge double %x, 0.000000e+00
@@ -184,9 +174,8 @@
 
 define double @select_noFMF_fsubfabs_olt(double %x) {
 ; CHECK-LABEL: @select_noFMF_fsubfabs_olt(
-; CHECK-NEXT:    [[CMP:%.*]] = fcmp olt double [[X:%.*]], 0.000000e+00
-; CHECK-NEXT:    [[SUB:%.*]] = fsub double 0.000000e+00, [[X]]
-; CHECK-NEXT:    [[RETVAL_0:%.*]] = select i1 [[CMP]], double [[X]], double [[SUB]]
+; CHECK-NEXT:    [[TMP1:%.*]] = call double @llvm.fabs.f64(double [[X:%.*]])
+; CHECK-NEXT:    [[RETVAL_0:%.*]] = fsub double 0.000000e+00, [[TMP1]]
 ; CHECK-NEXT:    ret double [[RETVAL_0]]
 ;
   %cmp = fcmp olt double %x, 0.000000e+00
@@ -197,9 +186,8 @@
 
 define double @select_noFMF_fsubfabs_ult(double %x) {
 ; CHECK-LABEL: @select_noFMF_fsubfabs_ult(
-; CHECK-NEXT:    [[CMP:%.*]] = fcmp ult double [[X:%.*]], 0.000000e+00
-; CHECK-NEXT:    [[SUB:%.*]] = fsub double 0.000000e+00, [[X]]
-; CHECK-NEXT:    [[RETVAL_0:%.*]] = select i1 [[CMP]], double [[X]], double [[SUB]]
+; CHECK-NEXT:    [[TMP1:%.*]] = call double @llvm.fabs.f64(double [[X:%.*]])
+; CHECK-NEXT:    [[RETVAL_0:%.*]] = fsub double 0.000000e+00, [[TMP1]]
 ; CHECK-NEXT:    ret double [[RETVAL_0]]
 ;
   %cmp = fcmp ult double %x, 0.000000e+00
@@ -213,9 +201,8 @@
 ; (X < +/-0.0) ? X : -X --> -fabs(X)
 define double @select_nsz_fnegfabs_olt(double %x) {
 ; CHECK-LABEL: @select_nsz_fnegfabs_olt(
-; CHECK-NEXT:    [[CMP:%.*]] = fcmp olt double [[X:%.*]], 0.000000e+00
-; CHECK-NEXT:    [[NEGX:%.*]] = fneg nsz double [[X]]
-; CHECK-NEXT:    [[RETVAL_0:%.*]] = select i1 [[CMP]], double [[X]], double [[NEGX]]
+; CHECK-NEXT:    [[TMP1:%.*]] = call double @llvm.fabs.f64(double [[X:%.*]])
+; CHECK-NEXT:    [[RETVAL_0:%.*]] = fneg nsz double [[TMP1]]
 ; CHECK-NEXT:    ret double [[RETVAL_0]]
 ;
   %cmp = fcmp olt double %x, 0.000000e+00
@@ -226,9 +213,8 @@
 
 define double @select_nsz_fnegfabs_ult(double %x) {
 ; CHECK-LABEL: @select_nsz_fnegfabs_ult(
-; CHECK-NEXT:    [[CMP:%.*]] = fcmp ult double [[X:%.*]], 0.000000e+00
-; CHECK-NEXT:    [[NEGX:%.*]] = fneg nsz double [[X]]
-; CHECK-NEXT:    [[RETVAL_0:%.*]] = select i1 [[CMP]], double [[X]], double [[NEGX]]
+; CHECK-NEXT:    [[TMP1:%.*]] = call double @llvm.fabs.f64(double [[X:%.*]])
+; CHECK-NEXT:    [[RETVAL_0:%.*]] = fneg nsz double [[TMP1]]
 ; CHECK-NEXT:    ret double [[RETVAL_0]]
 ;
   %cmp = fcmp ult double %x, 0.000000e+00