instcombine: Migrate isdigit optimizations

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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168578 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Transforms/Scalar/SimplifyLibCalls.cpp

@@ -99,25 +99,6 @@ namespace {
 // Integer Optimizations
 //===----------------------------------------------------------------------===//
 
-//===---------------------------------------===//
-// 'isdigit' Optimizations
-
-struct IsDigitOpt : 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;
-
-    // isdigit(c) -> (c-'0') <u 10
-    Value *Op = CI->getArgOperand(0);
-    Op = B.CreateSub(Op, B.getInt32('0'), "isdigittmp");
-    Op = B.CreateICmpULT(Op, B.getInt32(10), "isdigit");
-    return B.CreateZExt(Op, CI->getType());
-  }
-};
-
 //===---------------------------------------===//
 // 'isascii' Optimizations
 
@@ -521,7 +502,7 @@ namespace {
 
     StringMap<LibCallOptimization*> Optimizations;
     // Integer Optimizations
-    IsDigitOpt IsDigit; IsAsciiOpt IsAscii;
+    IsAsciiOpt IsAscii;
     ToAsciiOpt ToAscii;
     // Formatting and IO Optimizations
     SPrintFOpt SPrintF; PrintFOpt PrintF;
@@ -582,7 +563,6 @@ void SimplifyLibCalls::AddOpt(LibFunc::Func F1, LibFunc::Func F2,
 /// we know.
 void SimplifyLibCalls::InitOptimizations() {
   // Integer Optimizations
-  Optimizations["isdigit"] = &IsDigit;
   Optimizations["isascii"] = &IsAscii;
   Optimizations["toascii"] = &ToAscii;
 

lib/Transforms/Utils/SimplifyLibCalls.cpp

@@ -1267,6 +1267,22 @@ struct AbsOpt : public LibCallOptimization {
   }
 };
 
+struct IsDigitOpt : 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;
+
+    // isdigit(c) -> (c-'0') <u 10
+    Value *Op = CI->getArgOperand(0);
+    Op = B.CreateSub(Op, B.getInt32('0'), "isdigittmp");
+    Op = B.CreateICmpULT(Op, B.getInt32(10), "isdigit");
+    return B.CreateZExt(Op, CI->getType());
+  }
+};
+
 } // End anonymous namespace.
 
 namespace llvm {
@@ -1316,6 +1332,7 @@ class LibCallSimplifierImpl {
   // Integer library call optimizations.
   FFSOpt FFS;
   AbsOpt Abs;
+  IsDigitOpt IsDigit;
 
   void initOptimizations();
   void addOpt(LibFunc::Func F, LibCallOptimization* Opt);
@@ -1434,6 +1451,7 @@ void LibCallSimplifierImpl::initOptimizations() {
   addOpt(LibFunc::abs, &Abs);
   addOpt(LibFunc::labs, &Abs);
   addOpt(LibFunc::llabs, &Abs);
+  addOpt(LibFunc::isdigit, &IsDigit);
 }
 
 Value *LibCallSimplifierImpl::optimizeCall(CallInst *CI) {

test/Transforms/InstCombine/isdigit-1.ll

@@ -0,0 +1,48 @@
+; Test that the isdigit 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 @isdigit(i32)
+
+; Check isdigit(c) -> (c - '0') <u 10;
+
+define i32 @test_simplify1() {
+; CHECK: @test_simplify1
+  %ret = call i32 @isdigit(i32 47)
+  ret i32 %ret
+; CHECK-NEXT: ret i32 0
+}
+
+define i32 @test_simplify2() {
+; CHECK: @test_simplify2
+  %ret = call i32 @isdigit(i32 48)
+  ret i32 %ret
+; CHECK-NEXT: ret i32 1
+}
+
+define i32 @test_simplify3() {
+; CHECK: @test_simplify3
+  %ret = call i32 @isdigit(i32 57)
+  ret i32 %ret
+; CHECK-NEXT: ret i32 1
+}
+
+define i32 @test_simplify4() {
+; CHECK: @test_simplify4
+  %ret = call i32 @isdigit(i32 58)
+  ret i32 %ret
+; CHECK-NEXT: ret i32 0
+}
+
+define i32 @test_simplify5(i32 %x) {
+; CHECK: @test_simplify5
+
+  %ret = call i32 @isdigit(i32 %x)
+; CHECK-NEXT: [[ADD:%[a-z0-9]+]] = add i32 %x, -48
+; CHECK-NEXT: [[CMP:%[a-z0-9]+]] = icmp ult i32 [[ADD]], 10
+; CHECK-NEXT: [[ZEXT:%[a-z0-9]+]] = zext i1 [[CMP]] to i32
+  ret i32 %ret
+; CHECK-NEXT: ret i32 [[ZEXT]]
+}

test/Transforms/SimplifyLibCalls/IsDigit.ll

@@ -1,21 +0,0 @@
-; Test that the IsDigitOptimizer works correctly
-; RUN: opt < %s -simplify-libcalls -S | \
-; RUN:   not grep call
-
-declare i32 @isdigit(i32)
-
-declare i32 @isascii(i32)
-
-define i32 @main() {
-	%val1 = call i32 @isdigit( i32 47 )		; <i32> [#uses=1]
-	%val2 = call i32 @isdigit( i32 48 )		; <i32> [#uses=1]
-	%val3 = call i32 @isdigit( i32 57 )		; <i32> [#uses=1]
-	%val4 = call i32 @isdigit( i32 58 )		; <i32> [#uses=1]
-	%rslt1 = add i32 %val1, %val2		; <i32> [#uses=1]
-	%rslt2 = add i32 %val3, %val4		; <i32> [#uses=1]
-	%sum = add i32 %rslt1, %rslt2		; <i32> [#uses=1]
-	%rslt = call i32 @isdigit( i32 %sum )		; <i32> [#uses=1]
-	%tmp = call i32 @isascii( i32 %rslt )		; <i32> [#uses=1]
-	ret i32 %tmp
-}
-