Split -enable-finite-only-fp-math to two options:

-enable-no-nans-fp-math and -enable-no-infs-fp-math. All of the current codegen fp math optimizations only care whether the fp arithmetics arguments and results can never be NaN.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@108465 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Target/TargetOptions.h

@@ -71,13 +71,18 @@ namespace llvm {
   /// UnsafeFPMath implies LessPreciseFPMAD.
   extern bool UnsafeFPMath;
 
-  /// FiniteOnlyFPMath - This returns true when the -enable-finite-only-fp-math
+  /// NoInfsFPMath - This flag is enabled when the
-  /// option is specified on the command line. If this returns false (default),
+  /// -enable-no-infs-fp-math flag is specified on the command line. When
-  /// the code generator is not allowed to assume that FP arithmetic arguments
+  /// this flag is off (the default), the code generator is not allowed to
-  /// and results are never NaNs or +-Infs.
+  /// assume the FP arithmetic arguments and results are never +-Infs.
-  extern bool FiniteOnlyFPMathOption;
+  extern bool NoInfsFPMath;
-  extern bool FiniteOnlyFPMath();
+
-  
+  /// NoNaNsFPMath - This flag is enabled when the
+  /// -enable-no-nans-fp-math flag is specified on the command line. When
+  /// this flag is off (the default), the code generator is not allowed to
+  /// assume the FP arithmetic arguments and results are never NaNs.
+  extern bool NoNaNsFPMath;
+
   /// HonorSignDependentRoundingFPMath - This returns true when the
   /// -enable-sign-dependent-rounding-fp-math is specified.  If this returns
   /// false (the default), the code generator is allowed to assume that the

lib/CodeGen/Analysis.cpp

@@ -171,7 +171,7 @@ ISD::CondCode llvm::getFCmpCondCode(FCmpInst::Predicate Pred) {
     FOC = FPC = ISD::SETFALSE;
     break;
   }
-  if (FiniteOnlyFPMath())
+  if (NoNaNsFPMath)
     return FOC;
   else
     return FPC;

lib/CodeGen/SelectionDAG/SelectionDAG.cpp

@@ -2236,7 +2236,7 @@ unsigned SelectionDAG::ComputeNumSignBits(SDValue Op, unsigned Depth) const{
 
 bool SelectionDAG::isKnownNeverNaN(SDValue Op) const {
   // If we're told that NaNs won't happen, assume they won't.
-  if (FiniteOnlyFPMath())
+  if (NoNaNsFPMath)
     return true;
 
   // If the value is a constant, we can obviously see if it is a NaN or not.

lib/Target/ARM/ARMISelLowering.cpp

@@ -2403,8 +2403,9 @@ ARMTargetLowering::OptimizeVFPBrcond(SDValue Op, SelectionDAG &DAG) const {
   bool SeenZero = false;
   if (canChangeToInt(LHS, SeenZero, Subtarget) &&
       canChangeToInt(RHS, SeenZero, Subtarget) &&
-      // If one of the operand is zero, it's safe to ignore the NaN case.
+      // If one of the operand is zero, it's safe to ignore the NaN case since
-      (FiniteOnlyFPMath() || SeenZero)) {
+      // we only care about equality comparisons.
+      (SeenZero || (DAG.isKnownNeverNaN(LHS) && DAG.isKnownNeverNaN(RHS)))) {
     // If unsafe fp math optimization is enabled and there are no othter uses of
     // the CMP operands, and the condition code is EQ oe NE, we can optimize it
     // to an integer comparison.
@@ -4561,7 +4562,7 @@ static SDValue PerformExtendCombine(SDNode *N, SelectionDAG &DAG,
 static SDValue PerformSELECT_CCCombine(SDNode *N, SelectionDAG &DAG,
                                        const ARMSubtarget *ST) {
   // If the target supports NEON, try to use vmax/vmin instructions for f32
-  // selects like "x < y ? x : y".  Unless the FiniteOnlyFPMath option is set,
+  // selects like "x < y ? x : y".  Unless the NoNaNsFPMath option is set,
   // be careful about NaNs:  NEON's vmax/vmin return NaN if either operand is
   // a NaN; only do the transformation when it matches that behavior.
 

lib/Target/ARM/AsmPrinter/ARMAsmPrinter.cpp

@@ -1174,7 +1174,7 @@ void ARMAsmPrinter::EmitStartOfAsmFile(Module &M) {
                               Twine(ARMBuildAttrs::ABI_FP_exceptions) + ", 1");
     }
     
-    if (FiniteOnlyFPMath())
+    if (NoInfsFPMath && NoNaNsFPMath)
       OutStreamer.EmitRawText("\t.eabi_attribute " +
                               Twine(ARMBuildAttrs::ABI_FP_number_model)+ ", 1");
     else

lib/Target/TargetMachine.cpp

@@ -30,7 +30,8 @@ namespace llvm {
   bool NoFramePointerElimNonLeaf;
   bool NoExcessFPPrecision;
   bool UnsafeFPMath;
-  bool FiniteOnlyFPMathOption;
+  bool NoInfsFPMath;
+  bool NoNaNsFPMath;
   bool HonorSignDependentRoundingFPMathOption;
   bool UseSoftFloat;
   FloatABI::ABIType FloatABIType;
@@ -80,9 +81,14 @@ EnableUnsafeFPMath("enable-unsafe-fp-math",
   cl::location(UnsafeFPMath),
   cl::init(false));
 static cl::opt<bool, true>
-EnableFiniteOnlyFPMath("enable-finite-only-fp-math",
+EnableNoInfsFPMath("enable-no-infs-fp-math",
-  cl::desc("Enable optimizations that assumes non- NaNs / +-Infs"),
+  cl::desc("Enable FP math optimizations that assume no +-Infs"),
-  cl::location(FiniteOnlyFPMathOption),
+  cl::location(NoInfsFPMath),
+  cl::init(false));
+static cl::opt<bool, true>
+EnableNoNaNsFPMath("enable-no-nans-fp-math",
+  cl::desc("Enable FP math optimizations that assume no NaNs"),
+  cl::location(NoNaNsFPMath),
   cl::init(false));
 static cl::opt<bool, true>
 EnableHonorSignDependentRoundingFPMath("enable-sign-dependent-rounding-fp-math",
@@ -290,12 +296,6 @@ namespace llvm {
   /// result is "less precise" than doing those operations individually.
   bool LessPreciseFPMAD() { return UnsafeFPMath || LessPreciseFPMADOption; }
 
-  /// FiniteOnlyFPMath - This returns true when the -enable-finite-only-fp-math
-  /// option is specified on the command line. If this returns false (default),
-  /// the code generator is not allowed to assume that FP arithmetic arguments
-  /// and results are never NaNs or +-Infs.
-  bool FiniteOnlyFPMath() { return FiniteOnlyFPMathOption; }
-  
   /// HonorSignDependentRoundingFPMath - Return true if the codegen must assume
   /// that the rounding mode of the FPU can change from its default.
   bool HonorSignDependentRoundingFPMath() {

lib/Target/X86/X86ISelLowering.cpp

@@ -9087,8 +9087,7 @@ static SDValue PerformSELECTCombine(SDNode *N, SelectionDAG &DAG,
         // Converting this to a min would handle NaNs incorrectly, and swapping
         // the operands would cause it to handle comparisons between positive
         // and negative zero incorrectly.
-        if (!FiniteOnlyFPMath() &&
+        if (!DAG.isKnownNeverNaN(LHS) || !DAG.isKnownNeverNaN(RHS)) {
-            (!DAG.isKnownNeverNaN(LHS) || !DAG.isKnownNeverNaN(RHS))) {
           if (!UnsafeFPMath &&
               !(DAG.isKnownNeverZero(LHS) || DAG.isKnownNeverZero(RHS)))
             break;
@@ -9126,8 +9125,7 @@ static SDValue PerformSELECTCombine(SDNode *N, SelectionDAG &DAG,
         // Converting this to a max would handle NaNs incorrectly, and swapping
         // the operands would cause it to handle comparisons between positive
         // and negative zero incorrectly.
-        if (!FiniteOnlyFPMath() &&
+        if (!DAG.isKnownNeverNaN(LHS) || !DAG.isKnownNeverNaN(RHS)) {
-            (!DAG.isKnownNeverNaN(LHS) || !DAG.isKnownNeverNaN(RHS))) {
           if (!UnsafeFPMath &&
               !(DAG.isKnownNeverZero(LHS) || DAG.isKnownNeverZero(RHS)))
             break;
@@ -9156,8 +9154,7 @@ static SDValue PerformSELECTCombine(SDNode *N, SelectionDAG &DAG,
         // cause it to handle NaNs incorrectly.
         if (!UnsafeFPMath &&
             !(DAG.isKnownNeverZero(LHS) || DAG.isKnownNeverZero(RHS))) {
-          if (!FiniteOnlyFPMath() &&
+          if (!DAG.isKnownNeverNaN(LHS) || !DAG.isKnownNeverNaN(RHS))
-              (!DAG.isKnownNeverNaN(LHS) || !DAG.isKnownNeverNaN(RHS)))
             break;
           std::swap(LHS, RHS);
         }
@@ -9182,8 +9179,7 @@ static SDValue PerformSELECTCombine(SDNode *N, SelectionDAG &DAG,
 
       case ISD::SETULT:
         // Converting this to a max would handle NaNs incorrectly.
-        if (!FiniteOnlyFPMath() &&
+        if (!DAG.isKnownNeverNaN(LHS) || !DAG.isKnownNeverNaN(RHS))
-            (!DAG.isKnownNeverNaN(LHS) || !DAG.isKnownNeverNaN(RHS)))
           break;
         Opcode = X86ISD::FMAX;
         break;
@@ -9193,8 +9189,7 @@ static SDValue PerformSELECTCombine(SDNode *N, SelectionDAG &DAG,
         // cause it to handle NaNs incorrectly.
         if (!UnsafeFPMath &&
             !DAG.isKnownNeverZero(LHS) && !DAG.isKnownNeverZero(RHS)) {
-          if (!FiniteOnlyFPMath() &&
+          if (!DAG.isKnownNeverNaN(LHS) || !DAG.isKnownNeverNaN(RHS))
-              (!DAG.isKnownNeverNaN(LHS) || !DAG.isKnownNeverNaN(RHS)))
             break;
           std::swap(LHS, RHS);
         }

test/CodeGen/ARM/fpcmp-opt.ll

@@ -1,4 +1,4 @@
-; RUN: llc < %s -march=arm -mcpu=cortex-a8 -mattr=+vfp2 -enable-unsafe-fp-math -enable-finite-only-fp-math | FileCheck -check-prefix=FINITE %s
+; RUN: llc < %s -march=arm -mcpu=cortex-a8 -mattr=+vfp2 -enable-unsafe-fp-math -enable-no-nans-fp-math | FileCheck -check-prefix=FINITE %s
 ; RUN: llc < %s -march=arm -mcpu=cortex-a8 -mattr=+vfp2 -enable-unsafe-fp-math | FileCheck -check-prefix=NAN %s
 ; rdar://7461510
 

test/CodeGen/X86/2006-05-22-FPSetEQ.ll

@@ -1,5 +1,5 @@
 ; RUN: llc < %s -march=x86 | grep setnp
-; RUN: llc < %s -march=x86 -enable-unsafe-fp-math -enable-finite-only-fp-math | \
+; RUN: llc < %s -march=x86 -enable-unsafe-fp-math -enable-no-nans-fp-math | \
 ; RUN:   not grep setnp
 
 define i32 @test(float %f) {

test/CodeGen/X86/fabs.ll

@@ -1,7 +1,7 @@
 ; Make sure this testcase codegens to the fabs instruction, not a call to fabsf
 ; RUN: llc < %s -march=x86 -mattr=-sse2,-sse3,-sse | grep fabs\$ | \
 ; RUN:   count 2
-; RUN: llc < %s -march=x86 -mattr=-sse,-sse2,-sse3 -enable-unsafe-fp-math -enable-finite-only-fp-math | \
+; RUN: llc < %s -march=x86 -mattr=-sse,-sse2,-sse3 -enable-unsafe-fp-math -enable-no-nans-fp-math | \
 ; RUN:   grep fabs\$ | count 3
 
 declare float @fabsf(float)

test/CodeGen/X86/sse-minmax.ll

@@ -1,6 +1,6 @@
 ; RUN: llc < %s -march=x86-64 -asm-verbose=false | FileCheck %s
-; RUN: llc < %s -march=x86-64 -asm-verbose=false -enable-unsafe-fp-math -enable-finite-only-fp-math | FileCheck -check-prefix=UNSAFE %s
+; RUN: llc < %s -march=x86-64 -asm-verbose=false -enable-unsafe-fp-math -enable-no-nans-fp-math | FileCheck -check-prefix=UNSAFE %s
-; RUN: llc < %s -march=x86-64 -asm-verbose=false -enable-finite-only-fp-math | FileCheck -check-prefix=FINITE %s
+; RUN: llc < %s -march=x86-64 -asm-verbose=false -enable-no-nans-fp-math | FileCheck -check-prefix=FINITE %s
 
 ; Some of these patterns can be matched as SSE min or max. Some of
 ; then can be matched provided that the operands are swapped.