[llvm-commits] [llvm] r167082 - in /llvm/trunk: lib/Transforms/Utils/SimplifyLibCalls.cpp test/Transforms/InstCombine/stpcpy_chk-1.ll test/Transforms/InstCombine/stpcpy_chk-2.ll
Meador Inge
meadori at codesourcery.com
Tue Oct 30 17:20:51 PDT 2012
Author: meadori
Date: Tue Oct 30 19:20:51 2012
New Revision: 167082
URL: http://llvm.org/viewvc/llvm-project?rev=167082&view=rev
Log:
instcombine: Split out the __stpcpy_chk simplifications from StrCpyChkOpt
r166198 migrated the strcpy optimization to instcombine. The strcpy
simplifier that was migrated from Transforms/Scalar/SimplifyLibCalls.cpp
was also doing some __strcpy_chk simplifications. Those fortified
simplifications were migrated as well, but introduced a bug in the
__stpcpy_chk simplifier in the process. This happened because the
__strcpy_chk and __stpcpy_chk simplifiers were both mapped to StrCpyChkOpt
which was updated with simplifications that worked for __strcpy_chk, but
not __stpcpy_chk.
This patch fixes the problem by adding proper test coverage and creating a
new simplifier for __stpcpy_chk (instead of sharing one with __strcpy_chk).
Added:
llvm/trunk/test/Transforms/InstCombine/stpcpy_chk-1.ll
llvm/trunk/test/Transforms/InstCombine/stpcpy_chk-2.ll
Modified:
llvm/trunk/lib/Transforms/Utils/SimplifyLibCalls.cpp
Modified: llvm/trunk/lib/Transforms/Utils/SimplifyLibCalls.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/SimplifyLibCalls.cpp?rev=167082&r1=167081&r2=167082&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/SimplifyLibCalls.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/SimplifyLibCalls.cpp Tue Oct 30 19:20:51 2012
@@ -185,8 +185,8 @@
return Src;
// If a) we don't have any length information, or b) we know this will
- // fit then just lower to a plain st[rp]cpy. Otherwise we'll keep our
- // st[rp]cpy_chk call which may fail at runtime if the size is too long.
+ // fit then just lower to a plain strcpy. Otherwise we'll keep our
+ // strcpy_chk call which may fail at runtime if the size is too long.
// TODO: It might be nice to get a maximum length out of the possible
// string lengths for varying.
if (isFoldable(2, 1, true)) {
@@ -210,6 +210,56 @@
}
};
+struct StpCpyChkOpt : public InstFortifiedLibCallOptimization {
+ virtual Value *callOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
+ this->CI = CI;
+ StringRef Name = Callee->getName();
+ FunctionType *FT = Callee->getFunctionType();
+ LLVMContext &Context = CI->getParent()->getContext();
+
+ // Check if this has the right signature.
+ if (FT->getNumParams() != 3 ||
+ FT->getReturnType() != FT->getParamType(0) ||
+ FT->getParamType(0) != FT->getParamType(1) ||
+ FT->getParamType(0) != Type::getInt8PtrTy(Context) ||
+ FT->getParamType(2) != TD->getIntPtrType(FT->getParamType(0)))
+ return 0;
+
+ Value *Dst = CI->getArgOperand(0), *Src = CI->getArgOperand(1);
+ if (Dst == Src) { // stpcpy(x,x) -> x+strlen(x)
+ Value *StrLen = EmitStrLen(Src, B, TD, TLI);
+ return StrLen ? B.CreateInBoundsGEP(Dst, StrLen) : 0;
+ }
+
+ // If a) we don't have any length information, or b) we know this will
+ // fit then just lower to a plain stpcpy. Otherwise we'll keep our
+ // stpcpy_chk call which may fail at runtime if the size is too long.
+ // TODO: It might be nice to get a maximum length out of the possible
+ // string lengths for varying.
+ if (isFoldable(2, 1, true)) {
+ Value *Ret = EmitStrCpy(Dst, Src, B, TD, TLI, Name.substr(2, 6));
+ return Ret;
+ } else {
+ // Maybe we can stil fold __stpcpy_chk to __memcpy_chk.
+ uint64_t Len = GetStringLength(Src);
+ if (Len == 0) return 0;
+
+ // This optimization require DataLayout.
+ if (!TD) return 0;
+
+ Type *PT = FT->getParamType(0);
+ Value *LenV = ConstantInt::get(TD->getIntPtrType(PT), Len);
+ Value *DstEnd = B.CreateGEP(Dst,
+ ConstantInt::get(TD->getIntPtrType(PT),
+ Len - 1));
+ if (!EmitMemCpyChk(Dst, Src, LenV, CI->getArgOperand(2), B, TD, TLI))
+ return 0;
+ return DstEnd;
+ }
+ return 0;
+ }
+};
+
struct StrNCpyChkOpt : public InstFortifiedLibCallOptimization {
virtual Value *callOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
this->CI = CI;
@@ -556,6 +606,7 @@
MemMoveChkOpt MemMoveChk;
MemSetChkOpt MemSetChk;
StrCpyChkOpt StrCpyChk;
+ StpCpyChkOpt StpCpyChk;
StrNCpyChkOpt StrNCpyChk;
// String and memory library call optimizations.
@@ -583,7 +634,7 @@
Optimizations["__memmove_chk"] = &MemMoveChk;
Optimizations["__memset_chk"] = &MemSetChk;
Optimizations["__strcpy_chk"] = &StrCpyChk;
- Optimizations["__stpcpy_chk"] = &StrCpyChk;
+ Optimizations["__stpcpy_chk"] = &StpCpyChk;
Optimizations["__strncpy_chk"] = &StrNCpyChk;
Optimizations["__stpncpy_chk"] = &StrNCpyChk;
Added: llvm/trunk/test/Transforms/InstCombine/stpcpy_chk-1.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/stpcpy_chk-1.ll?rev=167082&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/stpcpy_chk-1.ll (added)
+++ llvm/trunk/test/Transforms/InstCombine/stpcpy_chk-1.ll Tue Oct 30 19:20:51 2012
@@ -0,0 +1,96 @@
+; Test lib call simplification of __stpcpy_chk calls with various values
+; for src, dst, and slen.
+;
+; 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"
+
+ at a = common global [60 x i8] zeroinitializer, align 1
+ at b = common global [60 x i8] zeroinitializer, align 1
+ at .str = private constant [12 x i8] c"abcdefghijk\00"
+
+; Check cases where slen >= strlen (src).
+
+define void @test_simplify1() {
+; CHECK: @test_simplify1
+ %dst = getelementptr inbounds [60 x i8]* @a, i32 0, i32 0
+ %src = getelementptr inbounds [12 x i8]* @.str, i32 0, i32 0
+
+; CHECK-NEXT: call i8* @stpcpy
+ call i8* @__stpcpy_chk(i8* %dst, i8* %src, i32 60)
+ ret void
+}
+
+define void @test_simplify2() {
+; CHECK: @test_simplify2
+ %dst = getelementptr inbounds [60 x i8]* @a, i32 0, i32 0
+ %src = getelementptr inbounds [12 x i8]* @.str, i32 0, i32 0
+
+; CHECK-NEXT: call i8* @stpcpy
+ call i8* @__stpcpy_chk(i8* %dst, i8* %src, i32 12)
+ ret void
+}
+
+define void @test_simplify3() {
+; CHECK: @test_simplify3
+ %dst = getelementptr inbounds [60 x i8]* @a, i32 0, i32 0
+ %src = getelementptr inbounds [12 x i8]* @.str, i32 0, i32 0
+
+; CHECK-NEXT: call i8* @stpcpy
+ call i8* @__stpcpy_chk(i8* %dst, i8* %src, i32 -1)
+ ret void
+}
+
+; Check cases where there are no string constants.
+
+define void @test_simplify4() {
+; CHECK: @test_simplify4
+ %dst = getelementptr inbounds [60 x i8]* @a, i32 0, i32 0
+ %src = getelementptr inbounds [60 x i8]* @b, i32 0, i32 0
+
+; CHECK-NEXT: call i8* @stpcpy
+ call i8* @__stpcpy_chk(i8* %dst, i8* %src, i32 -1)
+ ret void
+}
+
+; Check case where the string length is not constant.
+
+define i8* @test_simplify5() {
+; CHECK: @test_simplify5
+ %dst = getelementptr inbounds [60 x i8]* @a, i32 0, i32 0
+ %src = getelementptr inbounds [12 x i8]* @.str, i32 0, i32 0
+
+; CHECK: @__memcpy_chk
+ %len = call i32 @llvm.objectsize.i32(i8* %dst, i1 false)
+ %ret = call i8* @__stpcpy_chk(i8* %dst, i8* %src, i32 %len)
+; CHECK: ret i8* getelementptr inbounds ([60 x i8]* @a, i32 0, i32 11)
+ ret i8* %ret
+}
+
+; Check case where the source and destination are the same.
+
+define i8* @test_simplify6() {
+; CHECK: @test_simplify6
+ %dst = getelementptr inbounds [60 x i8]* @a, i32 0, i32 0
+
+; CHECK: [[LEN:%[a-z]+]] = call i32 @strlen
+; CHECK-NEXT: getelementptr inbounds [60 x i8]* @a, i32 0, i32 [[LEN]]
+ %len = call i32 @llvm.objectsize.i32(i8* %dst, i1 false)
+ %ret = call i8* @__stpcpy_chk(i8* %dst, i8* %dst, i32 %len)
+ ret i8* %ret
+}
+
+; Check case where slen < strlen (src).
+
+define void @test_no_simplify1() {
+; CHECK: @test_no_simplify1
+ %dst = getelementptr inbounds [60 x i8]* @a, i32 0, i32 0
+ %src = getelementptr inbounds [60 x i8]* @b, i32 0, i32 0
+
+; CHECK-NEXT: call i8* @__stpcpy_chk
+ call i8* @__stpcpy_chk(i8* %dst, i8* %src, i32 8)
+ ret void
+}
+
+declare i8* @__stpcpy_chk(i8*, i8*, i32) nounwind
+declare i32 @llvm.objectsize.i32(i8*, i1) nounwind readonly
Added: llvm/trunk/test/Transforms/InstCombine/stpcpy_chk-2.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/stpcpy_chk-2.ll?rev=167082&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/stpcpy_chk-2.ll (added)
+++ llvm/trunk/test/Transforms/InstCombine/stpcpy_chk-2.ll Tue Oct 30 19:20:51 2012
@@ -0,0 +1,21 @@
+; Test that lib call simplification doesn't simplify __stpcpy_chk calls
+; with the wrong prototype.
+;
+; 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"
+
+ at a = common global [60 x i16] zeroinitializer, align 1
+ at .str = private constant [8 x i8] c"abcdefg\00"
+
+define void @test_no_simplify() {
+; CHECK: @test_no_simplify
+ %dst = getelementptr inbounds [60 x i16]* @a, i32 0, i32 0
+ %src = getelementptr inbounds [8 x i8]* @.str, i32 0, i32 0
+
+; CHECK-NEXT: call i16* @__strcpy_chk
+ call i16* @__strcpy_chk(i16* %dst, i8* %src, i32 8)
+ ret void
+}
+
+declare i16* @__strcpy_chk(i16*, i8*, i32)
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