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-rw-r--r--llvm/lib/Transforms/Scalar/SimplifyLibCalls.cpp45
-rw-r--r--llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp44
-rw-r--r--llvm/test/Transforms/InstCombine/strlen-1.ll97
-rw-r--r--llvm/test/Transforms/InstCombine/strlen-2.ll18
-rw-r--r--llvm/test/Transforms/SimplifyLibCalls/StrLen.ll62
5 files changed, 160 insertions, 106 deletions
diff --git a/llvm/lib/Transforms/Scalar/SimplifyLibCalls.cpp b/llvm/lib/Transforms/Scalar/SimplifyLibCalls.cpp
index 4251e60a916..a0235c15b61 100644
--- a/llvm/lib/Transforms/Scalar/SimplifyLibCalls.cpp
+++ b/llvm/lib/Transforms/Scalar/SimplifyLibCalls.cpp
@@ -90,22 +90,6 @@ public:
// Helper Functions
//===----------------------------------------------------------------------===//
-/// IsOnlyUsedInZeroEqualityComparison - Return true if it only matters that the
-/// value is equal or not-equal to zero.
-static bool IsOnlyUsedInZeroEqualityComparison(Value *V) {
- for (Value::use_iterator UI = V->use_begin(), E = V->use_end();
- UI != E; ++UI) {
- if (ICmpInst *IC = dyn_cast<ICmpInst>(*UI))
- if (IC->isEquality())
- if (Constant *C = dyn_cast<Constant>(IC->getOperand(1)))
- if (C->isNullValue())
- continue;
- // Unknown instruction.
- return false;
- }
- return true;
-}
-
static bool CallHasFloatingPointArgument(const CallInst *CI) {
for (CallInst::const_op_iterator it = CI->op_begin(), e = CI->op_end();
it != e; ++it) {
@@ -135,32 +119,6 @@ static bool IsOnlyUsedInEqualityComparison(Value *V, Value *With) {
namespace {
//===---------------------------------------===//
-// 'strlen' Optimizations
-
-struct StrLenOpt : public LibCallOptimization {
- virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
- FunctionType *FT = Callee->getFunctionType();
- if (FT->getNumParams() != 1 ||
- FT->getParamType(0) != B.getInt8PtrTy() ||
- !FT->getReturnType()->isIntegerTy())
- return 0;
-
- Value *Src = CI->getArgOperand(0);
-
- // Constant folding: strlen("xyz") -> 3
- if (uint64_t Len = GetStringLength(Src))
- return ConstantInt::get(CI->getType(), Len-1);
-
- // strlen(x) != 0 --> *x != 0
- // strlen(x) == 0 --> *x == 0
- if (IsOnlyUsedInZeroEqualityComparison(CI))
- return B.CreateZExt(B.CreateLoad(Src, "strlenfirst"), CI->getType());
- return 0;
- }
-};
-
-
-//===---------------------------------------===//
// 'strpbrk' Optimizations
struct StrPBrkOpt : public LibCallOptimization {
@@ -1146,7 +1104,7 @@ namespace {
StringMap<LibCallOptimization*> Optimizations;
// String and Memory LibCall Optimizations
- StrLenOpt StrLen; StrPBrkOpt StrPBrk;
+ StrPBrkOpt StrPBrk;
StrToOpt StrTo; StrSpnOpt StrSpn; StrCSpnOpt StrCSpn; StrStrOpt StrStr;
MemCmpOpt MemCmp; MemCpyOpt MemCpy; MemMoveOpt MemMove; MemSetOpt MemSet;
// Math Library Optimizations
@@ -1215,7 +1173,6 @@ void SimplifyLibCalls::AddOpt(LibFunc::Func F1, LibFunc::Func F2,
/// we know.
void SimplifyLibCalls::InitOptimizations() {
// String and Memory LibCall Optimizations
- Optimizations["strlen"] = &StrLen;
Optimizations["strpbrk"] = &StrPBrk;
Optimizations["strtol"] = &StrTo;
Optimizations["strtod"] = &StrTo;
diff --git a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
index cc03573326e..658e7c34287 100644
--- a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
@@ -64,6 +64,26 @@ public:
};
//===----------------------------------------------------------------------===//
+// Helper Functions
+//===----------------------------------------------------------------------===//
+
+/// isOnlyUsedInZeroEqualityComparison - Return true if it only matters that the
+/// value is equal or not-equal to zero.
+static bool isOnlyUsedInZeroEqualityComparison(Value *V) {
+ for (Value::use_iterator UI = V->use_begin(), E = V->use_end();
+ UI != E; ++UI) {
+ if (ICmpInst *IC = dyn_cast<ICmpInst>(*UI))
+ if (IC->isEquality())
+ if (Constant *C = dyn_cast<Constant>(IC->getOperand(1)))
+ if (C->isNullValue())
+ continue;
+ // Unknown instruction.
+ return false;
+ }
+ return true;
+}
+
+//===----------------------------------------------------------------------===//
// Fortified Library Call Optimizations
//===----------------------------------------------------------------------===//
@@ -675,6 +695,28 @@ struct StrNCpyOpt : public LibCallOptimization {
}
};
+struct StrLenOpt : public LibCallOptimization {
+ virtual Value *callOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
+ FunctionType *FT = Callee->getFunctionType();
+ if (FT->getNumParams() != 1 ||
+ FT->getParamType(0) != B.getInt8PtrTy() ||
+ !FT->getReturnType()->isIntegerTy())
+ return 0;
+
+ Value *Src = CI->getArgOperand(0);
+
+ // Constant folding: strlen("xyz") -> 3
+ if (uint64_t Len = GetStringLength(Src))
+ return ConstantInt::get(CI->getType(), Len-1);
+
+ // strlen(x) != 0 --> *x != 0
+ // strlen(x) == 0 --> *x == 0
+ if (isOnlyUsedInZeroEqualityComparison(CI))
+ return B.CreateZExt(B.CreateLoad(Src, "strlenfirst"), CI->getType());
+ return 0;
+ }
+};
+
} // End anonymous namespace.
namespace llvm {
@@ -702,6 +744,7 @@ class LibCallSimplifierImpl {
StrCpyOpt StrCpy;
StpCpyOpt StpCpy;
StrNCpyOpt StrNCpy;
+ StrLenOpt StrLen;
void initOptimizations();
public:
@@ -733,6 +776,7 @@ void LibCallSimplifierImpl::initOptimizations() {
Optimizations["strcpy"] = &StrCpy;
Optimizations["stpcpy"] = &StpCpy;
Optimizations["strncpy"] = &StrNCpy;
+ Optimizations["strlen"] = &StrLen;
}
Value *LibCallSimplifierImpl::optimizeCall(CallInst *CI) {
diff --git a/llvm/test/Transforms/InstCombine/strlen-1.ll b/llvm/test/Transforms/InstCombine/strlen-1.ll
new file mode 100644
index 00000000000..6d7464a4cc8
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/strlen-1.ll
@@ -0,0 +1,97 @@
+; Test that the strlen 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"
+
+@hello = constant [6 x i8] c"hello\00"
+@null = constant [1 x i8] zeroinitializer
+@null_hello = constant [7 x i8] c"\00hello\00"
+@nullstring = constant i8 0
+@a = common global [32 x i8] zeroinitializer, align 1
+
+declare i32 @strlen(i8*)
+
+; Check strlen(string constant) -> integer constant.
+
+define i32 @test_simplify1() {
+; CHECK: @test_simplify1
+ %hello_p = getelementptr [6 x i8]* @hello, i32 0, i32 0
+ %hello_l = call i32 @strlen(i8* %hello_p)
+ ret i32 %hello_l
+; CHECK-NEXT: ret i32 5
+}
+
+define i32 @test_simplify2() {
+; CHECK: @test_simplify2
+ %null_p = getelementptr [1 x i8]* @null, i32 0, i32 0
+ %null_l = call i32 @strlen(i8* %null_p)
+ ret i32 %null_l
+; CHECK-NEXT: ret i32 0
+}
+
+define i32 @test_simplify3() {
+; CHECK: @test_simplify3
+ %null_hello_p = getelementptr [7 x i8]* @null_hello, i32 0, i32 0
+ %null_hello_l = call i32 @strlen(i8* %null_hello_p)
+ ret i32 %null_hello_l
+; CHECK-NEXT: ret i32 0
+}
+
+define i32 @test_simplify4() {
+; CHECK: @test_simplify4
+ %len = tail call i32 @strlen(i8* @nullstring) nounwind
+ ret i32 %len
+; CHECK-NEXT: ret i32 0
+}
+
+; Check strlen(x) == 0 --> *x == 0.
+
+define i1 @test_simplify5() {
+; CHECK: @test_simplify5
+ %hello_p = getelementptr [6 x i8]* @hello, i32 0, i32 0
+ %hello_l = call i32 @strlen(i8* %hello_p)
+ %eq_hello = icmp eq i32 %hello_l, 0
+ ret i1 %eq_hello
+; CHECK-NEXT: ret i1 false
+}
+
+define i1 @test_simplify6() {
+; CHECK: @test_simplify6
+ %null_p = getelementptr [1 x i8]* @null, i32 0, i32 0
+ %null_l = call i32 @strlen(i8* %null_p)
+ %eq_null = icmp eq i32 %null_l, 0
+ ret i1 %eq_null
+; CHECK-NEXT: ret i1 true
+}
+
+; Check strlen(x) != 0 --> *x != 0.
+
+define i1 @test_simplify7() {
+; CHECK: @test_simplify7
+ %hello_p = getelementptr [6 x i8]* @hello, i32 0, i32 0
+ %hello_l = call i32 @strlen(i8* %hello_p)
+ %ne_hello = icmp ne i32 %hello_l, 0
+ ret i1 %ne_hello
+; CHECK-NEXT: ret i1 true
+}
+
+define i1 @test_simplify8() {
+; CHECK: @test_simplify8
+ %null_p = getelementptr [1 x i8]* @null, i32 0, i32 0
+ %null_l = call i32 @strlen(i8* %null_p)
+ %ne_null = icmp ne i32 %null_l, 0
+ ret i1 %ne_null
+; CHECK-NEXT: ret i1 false
+}
+
+; Check cases that shouldn't be simplified.
+
+define i32 @test_no_simplify1() {
+; CHECK: @test_no_simplify1
+ %a_p = getelementptr [32 x i8]* @a, i32 0, i32 0
+ %a_l = call i32 @strlen(i8* %a_p)
+; CHECK-NEXT: %a_l = call i32 @strlen
+ ret i32 %a_l
+; CHECK-NEXT: ret i32 %a_l
+}
diff --git a/llvm/test/Transforms/InstCombine/strlen-2.ll b/llvm/test/Transforms/InstCombine/strlen-2.ll
new file mode 100644
index 00000000000..c4fd54c06db
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/strlen-2.ll
@@ -0,0 +1,18 @@
+; Test that the strlen 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"
+
+@hello = constant [6 x i8] c"hello\00"
+
+declare i32 @strlen(i8*, i32)
+
+define i32 @test_no_simplify1() {
+; CHECK: @test_no_simplify1
+ %hello_p = getelementptr [6 x i8]* @hello, i32 0, i32 0
+ %hello_l = call i32 @strlen(i8* %hello_p, i32 187)
+; CHECK-NEXT: %hello_l = call i32 @strlen
+ ret i32 %hello_l
+; CHECK-NEXT: ret i32 %hello_l
+}
diff --git a/llvm/test/Transforms/SimplifyLibCalls/StrLen.ll b/llvm/test/Transforms/SimplifyLibCalls/StrLen.ll
deleted file mode 100644
index 4a20bbd2ce8..00000000000
--- a/llvm/test/Transforms/SimplifyLibCalls/StrLen.ll
+++ /dev/null
@@ -1,62 +0,0 @@
-; Test that the StrCatOptimizer works correctly
-; RUN: opt < %s -simplify-libcalls -S | \
-; RUN: not grep "call.*strlen"
-
-target datalayout = "e-p:32:32"
-@hello = constant [6 x i8] c"hello\00" ; <[6 x i8]*> [#uses=3]
-@null = constant [1 x i8] zeroinitializer ; <[1 x i8]*> [#uses=3]
-@null_hello = constant [7 x i8] c"\00hello\00" ; <[7 x i8]*> [#uses=1]
-@nullstring = constant i8 0
-
-declare i32 @strlen(i8*)
-
-define i32 @test1() {
- %hello_p = getelementptr [6 x i8]* @hello, i32 0, i32 0 ; <i8*> [#uses=1]
- %hello_l = call i32 @strlen( i8* %hello_p ) ; <i32> [#uses=1]
- ret i32 %hello_l
-}
-
-define i32 @test2() {
- %null_p = getelementptr [1 x i8]* @null, i32 0, i32 0 ; <i8*> [#uses=1]
- %null_l = call i32 @strlen( i8* %null_p ) ; <i32> [#uses=1]
- ret i32 %null_l
-}
-
-define i32 @test3() {
- %null_hello_p = getelementptr [7 x i8]* @null_hello, i32 0, i32 0 ; <i8*> [#uses=1]
- %null_hello_l = call i32 @strlen( i8* %null_hello_p ) ; <i32> [#uses=1]
- ret i32 %null_hello_l
-}
-
-define i1 @test4() {
- %hello_p = getelementptr [6 x i8]* @hello, i32 0, i32 0 ; <i8*> [#uses=1]
- %hello_l = call i32 @strlen( i8* %hello_p ) ; <i32> [#uses=1]
- %eq_hello = icmp eq i32 %hello_l, 0 ; <i1> [#uses=1]
- ret i1 %eq_hello
-}
-
-define i1 @test5() {
- %null_p = getelementptr [1 x i8]* @null, i32 0, i32 0 ; <i8*> [#uses=1]
- %null_l = call i32 @strlen( i8* %null_p ) ; <i32> [#uses=1]
- %eq_null = icmp eq i32 %null_l, 0 ; <i1> [#uses=1]
- ret i1 %eq_null
-}
-
-define i1 @test6() {
- %hello_p = getelementptr [6 x i8]* @hello, i32 0, i32 0 ; <i8*> [#uses=1]
- %hello_l = call i32 @strlen( i8* %hello_p ) ; <i32> [#uses=1]
- %ne_hello = icmp ne i32 %hello_l, 0 ; <i1> [#uses=1]
- ret i1 %ne_hello
-}
-
-define i1 @test7() {
- %null_p = getelementptr [1 x i8]* @null, i32 0, i32 0 ; <i8*> [#uses=1]
- %null_l = call i32 @strlen( i8* %null_p ) ; <i32> [#uses=1]
- %ne_null = icmp ne i32 %null_l, 0 ; <i1> [#uses=1]
- ret i1 %ne_null
-}
-
-define i32 @test8() {
- %len = tail call i32 @strlen(i8* @nullstring) nounwind
- ret i32 %len
-}
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