instcombine: Migrate isascii optimizations

This patch migrates the isascii optimizations from the simplify-libcalls
pass into the instcombine library call simplifier.

llvm-svn: 168579

llvm/lib/Transforms/Scalar/SimplifyLibCalls.cpp

@@ -99,24 +99,6 @@ namespace {
 // Integer Optimizations
 //===----------------------------------------------------------------------===//
 
-//===---------------------------------------===//
-// 'isascii' Optimizations
-
-struct IsAsciiOpt : public LibCallOptimization {
-  virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
-    FunctionType *FT = Callee->getFunctionType();
-    // We require integer(i32)
-    if (FT->getNumParams() != 1 || !FT->getReturnType()->isIntegerTy() ||
-        !FT->getParamType(0)->isIntegerTy(32))
-      return 0;
-
-    // isascii(c) -> c <u 128
-    Value *Op = CI->getArgOperand(0);
-    Op = B.CreateICmpULT(Op, B.getInt32(128), "isascii");
-    return B.CreateZExt(Op, CI->getType());
-  }
-};
-
 //===---------------------------------------===//
 // 'toascii' Optimizations
 
@@ -502,7 +484,6 @@ namespace {
 
     StringMap<LibCallOptimization*> Optimizations;
     // Integer Optimizations
-    IsAsciiOpt IsAscii;
     ToAsciiOpt ToAscii;
     // Formatting and IO Optimizations
     SPrintFOpt SPrintF; PrintFOpt PrintF;
@@ -563,7 +544,6 @@ void SimplifyLibCalls::AddOpt(LibFunc::Func F1, LibFunc::Func F2,
 /// we know.
 void SimplifyLibCalls::InitOptimizations() {
   // Integer Optimizations
-  Optimizations["isascii"] = &IsAscii;
   Optimizations["toascii"] = &ToAscii;
 
   // Formatting and IO Optimizations

llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp

@@ -1283,6 +1283,21 @@ struct IsDigitOpt : public LibCallOptimization {
   }
 };
 
+struct IsAsciiOpt : public LibCallOptimization {
+  virtual Value *callOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
+    FunctionType *FT = Callee->getFunctionType();
+    // We require integer(i32)
+    if (FT->getNumParams() != 1 || !FT->getReturnType()->isIntegerTy() ||
+        !FT->getParamType(0)->isIntegerTy(32))
+      return 0;
+
+    // isascii(c) -> c <u 128
+    Value *Op = CI->getArgOperand(0);
+    Op = B.CreateICmpULT(Op, B.getInt32(128), "isascii");
+    return B.CreateZExt(Op, CI->getType());
+  }
+};
+
 } // End anonymous namespace.
 
 namespace llvm {
@@ -1333,6 +1348,7 @@ class LibCallSimplifierImpl {
   FFSOpt FFS;
   AbsOpt Abs;
   IsDigitOpt IsDigit;
+  IsAsciiOpt IsAscii;
 
   void initOptimizations();
   void addOpt(LibFunc::Func F, LibCallOptimization* Opt);
@@ -1452,6 +1468,7 @@ void LibCallSimplifierImpl::initOptimizations() {
   addOpt(LibFunc::labs, &Abs);
   addOpt(LibFunc::llabs, &Abs);
   addOpt(LibFunc::isdigit, &IsDigit);
+  addOpt(LibFunc::isascii, &IsAscii);
 }
 
 Value *LibCallSimplifierImpl::optimizeCall(CallInst *CI) {

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

@@ -0,0 +1,32 @@
+; Test that the isascii library call simplifier works correctly.
+;
+; RUN: opt < %s -instcombine -S | FileCheck %s
+
+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"
+
+declare i32 @isascii(i32)
+
+; Check isascii(c) -> c <u 128.
+
+define i32 @test_simplify1() {
+; CHECK: @test_simplify1
+  %ret = call i32 @isascii(i32 127)
+  ret i32 %ret
+; CHECK-NEXT: ret i32 1
+}
+
+define i32 @test_simplify2() {
+; CHECK: @test_simplify2
+  %ret = call i32 @isascii(i32 128)
+  ret i32 %ret
+; CHECK-NEXT: ret i32 0
+}
+
+define i32 @test_simplify3(i32 %x) {
+; CHECK: @test_simplify3
+  %ret = call i32 @isascii(i32 %x)
+; CHECK-NEXT: [[CMP:%[a-z0-9]+]] = icmp ult i32 %x, 128
+; CHECK-NEXT: [[ZEXT:%[a-z0-9]+]] = zext i1 [[CMP]] to i32
+  ret i32 %ret
+; CHECK-NEXT: ret i32 [[ZEXT]]
+}