Apply transformation on OS X 10.9+ and iOS 7.0+: pow(10, x) ―> __exp10(x)

llvm-svn: 196544

llvm/lib/Target/TargetLibraryInfo.cpp

@@ -401,6 +401,31 @@ static void initialize(TargetLibraryInfo &TLI, const Triple &T,
     TLI.setAvailableWithName(LibFunc::fputs, "fputs$UNIX2003");
   }
 
+  // exp10 and exp10f are not available on OS X until 10.9 and iOS until 7.0
+  // and their names are __exp10 and __exp10f. exp10l is not available on
+  // OS X or iOS.
+  if (T.isMacOSX()) {
+    TLI.setUnavailable(LibFunc::exp10l);
+    if (T.isMacOSXVersionLT(10, 9)) {
+      TLI.setUnavailable(LibFunc::exp10);
+      TLI.setUnavailable(LibFunc::exp10f);
+    } else {
+      TLI.setAvailableWithName(LibFunc::exp10, "__exp10");
+      TLI.setAvailableWithName(LibFunc::exp10f, "__exp10f");
+    }
+  }
+
+  if (T.getOS() == Triple::IOS) {
+    TLI.setUnavailable(LibFunc::exp10l);
+    if (T.isOSVersionLT(7, 0)) {
+      TLI.setUnavailable(LibFunc::exp10);
+      TLI.setUnavailable(LibFunc::exp10f);
+    } else {
+      TLI.setAvailableWithName(LibFunc::exp10, "__exp10");
+      TLI.setAvailableWithName(LibFunc::exp10f, "__exp10f");
+    }
+  }
+
   // iprintf and friends are only available on XCore and TCE.
   if (T.getArch() != Triple::xcore && T.getArch() != Triple::tce) {
     TLI.setUnavailable(LibFunc::iprintf);

llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp

@@ -1162,6 +1162,12 @@ struct PowOpt : public UnsafeFPLibCallOptimization {
           hasUnaryFloatFn(TLI, Op1->getType(), LibFunc::exp2, LibFunc::exp2f,
                           LibFunc::exp2l))
         return EmitUnaryFloatFnCall(Op2, "exp2", B, Callee->getAttributes());
+      // pow(10.0, x) -> exp10(x)
+      if (Op1C->isExactlyValue(10.0) &&
+          hasUnaryFloatFn(TLI, Op1->getType(), LibFunc::exp10, LibFunc::exp10f,
+                          LibFunc::exp10l))
+        return EmitUnaryFloatFnCall(Op2, TLI->getName(LibFunc::exp10), B,
+                                    Callee->getAttributes());
     }
 
     ConstantFP *Op2C = dyn_cast<ConstantFP>(Op2);

llvm/test/Transforms/InstCombine/pow-1.ll

 ; Test that the pow library call simplifier works correctly.
 ;
 ; RUN: opt < %s -instcombine -S | FileCheck %s
+; RUN: opt -instcombine -S < %s -mtriple=x86_64-apple-macosx10.9 | FileCheck %s --check-prefix=CHECK-EXP10
+; RUN: opt -instcombine -S < %s -mtriple=arm-apple-ios7.0 | FileCheck %s --check-prefix=CHECK-EXP10
+; RUN: opt -instcombine -S < %s -mtriple=x86_64-apple-macosx10.8 | FileCheck %s --check-prefix=CHECK-NO-EXP10
+; RUN: opt -instcombine -S < %s -mtriple=arm-apple-ios6.0 | FileCheck %s --check-prefix=CHECK-NO-EXP10
 ; rdar://7251832
 
 ; NOTE: The readonly attribute on the pow call should be preserved
@@ -163,5 +167,25 @@ define double @test_simplify17(double %x) {
 ; CHECK-NEXT: ret double [[SELECT]]
 }
 
+; Check pow(10.0, x) -> __exp10(x) on OS X 10.9+ and iOS 7.0+.
+
+define float @test_simplify18(float %x) {
+; CHECK-LABEL: @test_simplify18(
+  %retval = call float @powf(float 10.0, float %x)
+; CHECK-EXP10: [[EXP10F:%[_a-z0-9]+]] = call float @__exp10f(float %x) [[NUW_RO:#[0-9]+]]
+  ret float %retval
+; CHECK-EXP10: ret float [[EXP10F]]
+; CHECK-NO-EXP10: call float @powf
+}
+
+define double @test_simplify19(double %x) {
+; CHECK-LABEL: @test_simplify19(
+  %retval = call double @pow(double 10.0, double %x)
+; CHECK-EXP10: [[EXP10:%[_a-z0-9]+]] = call double @__exp10(double %x) [[NUW_RO]]
+  ret double %retval
+; CHECK-EXP10: ret double [[EXP10]]
+; CHECK-NO-EXP10: call double @pow
+}
+
 ; CHECK: attributes [[NUW_RO]] = { nounwind readonly }