SimplifyLibCalls: Push TLI through the exp2->ldexp transform.

For the odd case of platforms with exp2 available but not ldexp.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200795 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 64 insertions, 29 deletions

diff --git a/include/llvm/Target/TargetLibraryInfo.h b/include/llvm/Target/TargetLibraryInfo.h
index 3bd8101e21..d4f9f23305 100644
--- a/include/llvm/Target/TargetLibraryInfo.h
+++ b/include/llvm/Target/TargetLibraryInfo.h
@@ -352,6 +352,12 @@ namespace llvm {
       labs,
       /// int lchown(const char *path, uid_t owner, gid_t group);
       lchown,
+      /// double ldexp(double x, int n);
+      ldexp,
+      /// float ldexpf(float x, int n);
+      ldexpf,
+      /// long double ldexpl(long double x, int n);
+      ldexpl,
       /// long long int llabs(long long int j);
       llabs,
       /// double log(double x);
diff --git a/lib/Target/TargetLibraryInfo.cpp b/lib/Target/TargetLibraryInfo.cpp
index f5ebc43eb2..46cce84859 100644
--- a/lib/Target/TargetLibraryInfo.cpp
+++ b/lib/Target/TargetLibraryInfo.cpp
@@ -190,6 +190,9 @@ const char* TargetLibraryInfo::StandardNames[LibFunc::NumLibFuncs] =
     "isdigit",
     "labs",
     "lchown",
+    "ldexp",
+    "ldexpf",
+    "ldexpl",
     "llabs",
     "log",
     "log10",
@@ -432,6 +435,8 @@ static void initialize(TargetLibraryInfo &TLI, const Triple &T,
     TLI.setUnavailable(LibFunc::fminl);
     TLI.setUnavailable(LibFunc::fmodl);
     TLI.setUnavailable(LibFunc::frexpl);
+    TLI.setUnavailable(LibFunc::ldexpf);
+    TLI.setUnavailable(LibFunc::ldexpl);
     TLI.setUnavailable(LibFunc::logl);
     TLI.setUnavailable(LibFunc::modfl);
     TLI.setUnavailable(LibFunc::powl);
diff --git a/lib/Transforms/Utils/SimplifyLibCalls.cpp b/lib/Transforms/Utils/SimplifyLibCalls.cpp
index 8cc5453ea6..2ffd03668c 100644
--- a/lib/Transforms/Utils/SimplifyLibCalls.cpp
+++ b/lib/Transforms/Utils/SimplifyLibCalls.cpp
@@ -1274,37 +1274,37 @@ struct Exp2Opt : public UnsafeFPLibCallOptimization {
     Value *Op = CI->getArgOperand(0);
     // Turn exp2(sitofp(x)) -> ldexp(1.0, sext(x))  if sizeof(x) <= 32
     // Turn exp2(uitofp(x)) -> ldexp(1.0, zext(x))  if sizeof(x) < 32
-    Value *LdExpArg = 0;
-    if (SIToFPInst *OpC = dyn_cast<SIToFPInst>(Op)) {
-      if (OpC->getOperand(0)->getType()->getPrimitiveSizeInBits() <= 32)
-        LdExpArg = B.CreateSExt(OpC->getOperand(0), B.getInt32Ty());
-    } else if (UIToFPInst *OpC = dyn_cast<UIToFPInst>(Op)) {
-      if (OpC->getOperand(0)->getType()->getPrimitiveSizeInBits() < 32)
-        LdExpArg = B.CreateZExt(OpC->getOperand(0), B.getInt32Ty());
-    }
+    LibFunc::Func LdExp = LibFunc::ldexpl;
+    if (Op->getType()->isFloatTy())
+      LdExp = LibFunc::ldexpf;
+    else if (Op->getType()->isDoubleTy())
+      LdExp = LibFunc::ldexp;
+
+    if (TLI->has(LdExp)) {
+      Value *LdExpArg = 0;
+      if (SIToFPInst *OpC = dyn_cast<SIToFPInst>(Op)) {
+        if (OpC->getOperand(0)->getType()->getPrimitiveSizeInBits() <= 32)
+          LdExpArg = B.CreateSExt(OpC->getOperand(0), B.getInt32Ty());
+      } else if (UIToFPInst *OpC = dyn_cast<UIToFPInst>(Op)) {
+        if (OpC->getOperand(0)->getType()->getPrimitiveSizeInBits() < 32)
+          LdExpArg = B.CreateZExt(OpC->getOperand(0), B.getInt32Ty());
+      }
 
-    if (LdExpArg) {
-      const char *Name;
-      if (Op->getType()->isFloatTy())
-        Name = "ldexpf";
-      else if (Op->getType()->isDoubleTy())
-        Name = "ldexp";
-      else
-        Name = "ldexpl";
-
-      Constant *One = ConstantFP::get(*Context, APFloat(1.0f));
-      if (!Op->getType()->isFloatTy())
-        One = ConstantExpr::getFPExtend(One, Op->getType());
-
-      Module *M = Caller->getParent();
-      Value *Callee = M->getOrInsertFunction(Name, Op->getType(),
-                                             Op->getType(),
-                                             B.getInt32Ty(), NULL);
-      CallInst *CI = B.CreateCall2(Callee, One, LdExpArg);
-      if (const Function *F = dyn_cast<Function>(Callee->stripPointerCasts()))
-        CI->setCallingConv(F->getCallingConv());
+      if (LdExpArg) {
+        Constant *One = ConstantFP::get(*Context, APFloat(1.0f));
+        if (!Op->getType()->isFloatTy())
+          One = ConstantExpr::getFPExtend(One, Op->getType());
 
-      return CI;
+        Module *M = Caller->getParent();
+        Value *Callee =
+            M->getOrInsertFunction(TLI->getName(LdExp), Op->getType(),
+                                   Op->getType(), B.getInt32Ty(), NULL);
+        CallInst *CI = B.CreateCall2(Callee, One, LdExpArg);
+        if (const Function *F = dyn_cast<Function>(Callee->stripPointerCasts()))
+          CI->setCallingConv(F->getCallingConv());
+
+        return CI;
+      }
     }
     return Ret;
   }
diff --git a/test/Transforms/InstCombine/exp2-1.ll b/test/Transforms/InstCombine/exp2-1.ll
index 99fb9ecfd2..8e6a0e0d93 100644
--- a/test/Transforms/InstCombine/exp2-1.ll
+++ b/test/Transforms/InstCombine/exp2-1.ll
@@ -1,6 +1,7 @@
 ; Test that the exp2 library call simplifier works correctly.
 ;
 ; RUN: opt < %s -instcombine -S | FileCheck %s
+; RUN: opt < %s -instcombine -S -mtriple=i386-pc-win32 | FileCheck %s -check-prefix=CHECK-WIN
 
 target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
 
@@ -74,3 +75,26 @@ define float @test_simplify8(i8 zeroext %x) {
 ; CHECK: call float @ldexpf
   ret float %ret
 }
+
+declare double @llvm.exp2.f64(double)
+declare float @llvm.exp2.f32(float)
+
+define double @test_simplify9(i8 zeroext %x) {
+; CHECK-LABEL: @test_simplify9(
+; CHECK-WIN-LABEL: @test_simplify9(
+  %conv = uitofp i8 %x to double
+  %ret = call double @llvm.exp2.f64(double %conv)
+; CHECK: call double @ldexp
+; CHECK-WIN: call double @ldexp
+  ret double %ret
+}
+
+define float @test_simplify10(i8 zeroext %x) {
+; CHECK-LABEL: @test_simplify10(
+; CHECK-WIN-LABEL: @test_simplify10(
+  %conv = uitofp i8 %x to float
+  %ret = call float @llvm.exp2.f32(float %conv)
+; CHECK: call float @ldexpf
+; CHECK-WIN-NOT: call float @ldexpf
+  ret float %ret
+}