[llvm] ab9fc8b - [SLC] sprintf(dst, "%s", str) -> strcpy(dst, str)
Craig Topper via llvm-commits
llvm-commits at lists.llvm.org
Thu Aug 13 19:45:34 PDT 2020
This transform is only valid if the sprintf result is unused. sprintf
returns the number of characters copied. strcpy just returns the
destination pointer.
~Craig
On Thu, Aug 13, 2020 at 4:19 PM Dávid Bolvanský via llvm-commits <
llvm-commits at lists.llvm.org> wrote:
> Ok, i will do next time.
>
> > Dňa 14. 8. 2020 o 1:15 užívateľ Eli Friedman <efriedma at quicinc.com>
> napísal:
> >
> > I think I'd prefer to use pre-commit review for all functional changes
> to SimplifyLibCalls, even if you're confident the change is safe; it's very
> easy to get something subtly wrong.
> >
> > This patch LGTM.
> >
> > -Eli
> >
> > -----Original Message-----
> > From: llvm-commits <llvm-commits-bounces at lists.llvm.org> On Behalf Of
> Dávid Bolvanský via llvm-commits
> > Sent: Thursday, August 13, 2020 3:08 PM
> > To: llvm-commits at lists.llvm.org
> > Subject: [EXT] [llvm] ab9fc8b - [SLC] sprintf(dst, "%s", str) ->
> strcpy(dst, str)
> >
> >
> > Author: Dávid Bolvanský
> > Date: 2020-08-14T00:05:55+02:00
> > New Revision: ab9fc8bae805c785066779e76e7846aabad5609e
> >
> > URL:
> https://github.com/llvm/llvm-project/commit/ab9fc8bae805c785066779e76e7846aabad5609e
> > DIFF:
> https://github.com/llvm/llvm-project/commit/ab9fc8bae805c785066779e76e7846aabad5609e.diff
> >
> > LOG: [SLC] sprintf(dst, "%s", str) -> strcpy(dst, str)
> >
> > Solves 46489
> >
> > Added:
> >
> >
> > Modified:
> > llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
> > llvm/test/Transforms/InstCombine/2010-05-30-memcpy-Struct.ll
> > llvm/test/Transforms/InstCombine/sprintf-1.ll
> >
> > Removed:
> >
> >
> >
> >
> ################################################################################
> > diff --git a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
> b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
> > index 2f6e60fc09c4..b5f0f56029a4 100644
> > --- a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
> > +++ b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
> > @@ -2487,21 +2487,11 @@ Value
> *LibCallSimplifier::optimizeSPrintFString(CallInst *CI,
> > }
> >
> > if (FormatStr[1] == 's') {
> > - // sprintf(dest, "%s", str) -> llvm.memcpy(align 1 dest, align 1
> str,
> > - // strlen(str)+1)
> > + // sprintf(dest, "%s", str) -> strcpy(dest, str)
> > if (!CI->getArgOperand(2)->getType()->isPointerTy())
> > return nullptr;
> >
> > - Value *Len = emitStrLen(CI->getArgOperand(2), B, DL, TLI);
> > - if (!Len)
> > - return nullptr;
> > - Value *IncLen =
> > - B.CreateAdd(Len, ConstantInt::get(Len->getType(), 1), "leninc");
> > - B.CreateMemCpy(CI->getArgOperand(0), Align(1), CI->getArgOperand(2),
> > - Align(1), IncLen);
> > -
> > - // The sprintf result is the unincremented number of bytes in the
> string.
> > - return B.CreateIntCast(Len, CI->getType(), false);
> > + return emitStrCpy(CI->getArgOperand(0), CI->getArgOperand(2), B,
> TLI);
> > }
> > return nullptr;
> > }
> >
> > diff --git
> a/llvm/test/Transforms/InstCombine/2010-05-30-memcpy-Struct.ll
> b/llvm/test/Transforms/InstCombine/2010-05-30-memcpy-Struct.ll
> > index 51610698c244..e3cf763917a0 100644
> > --- a/llvm/test/Transforms/InstCombine/2010-05-30-memcpy-Struct.ll
> > +++ b/llvm/test/Transforms/InstCombine/2010-05-30-memcpy-Struct.ll
> > @@ -1,3 +1,4 @@
> > +; NOTE: Assertions have been autogenerated by
> utils/update_test_checks.py
> > ; RUN: opt -instcombine -S < %s | FileCheck %s
> > ; PR7265
> >
> > @@ -9,10 +10,14 @@ target triple = "x86_64-unknown-linux-gnu"
> > @.str = private constant [3 x i8] c"%s\00"
> >
> > define void @CopyEventArg(%union.anon* %ev) nounwind {
> > +; CHECK-LABEL: @CopyEventArg(
> > +; CHECK-NEXT: entry:
> > +; CHECK-NEXT: [[CSTR:%.*]] = bitcast %union.anon* [[EV:%.*]] to i8*
> > +; CHECK-NEXT: [[STRCPY:%.*]] = call i8* @strcpy(i8* nonnull
> dereferenceable(1) undef, i8* nonnull dereferenceable(1) [[CSTR]])
> > +; CHECK-NEXT: ret void
> > +;
> > entry:
> > %call = call i32 (i8*, i8*, ...) @sprintf(i8* undef, i8* getelementptr
> inbounds ([3 x i8], [3 x i8]* @.str, i64 0, i64 0), %union.anon* %ev)
> nounwind
> > -; CHECK: bitcast %union.anon* %ev to i8*
> > -; CHECK: call void @llvm.memcpy.p0i8.p0i8.i64
> > ret void
> > }
> >
> >
> > diff --git a/llvm/test/Transforms/InstCombine/sprintf-1.ll
> b/llvm/test/Transforms/InstCombine/sprintf-1.ll
> > index 9dbfecaecb31..77c2d4bbd9b6 100644
> > --- a/llvm/test/Transforms/InstCombine/sprintf-1.ll
> > +++ b/llvm/test/Transforms/InstCombine/sprintf-1.ll
> > @@ -81,19 +81,15 @@ define void @test_simplify4(i8* %dst) {
> > ret void
> > }
> >
> > -; Check sprintf(dst, "%s", str) -> llvm.memcpy(dest, str, strlen(str) +
> 1, 1).
> > +; Check sprintf(dst, "%s", str) -> strcpy(dst, str)
> >
> > define void @test_simplify5(i8* %dst, i8* %str) {
> > ; CHECK-LABEL: @test_simplify5(
> > -; CHECK-NEXT: [[STRLEN:%.*]] = call i32 @strlen(i8* nonnull
> dereferenceable(1) [[STR:%.*]])
> > -; CHECK-NEXT: [[LENINC:%.*]] = add i32 [[STRLEN]], 1
> > -; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 1
> [[DST:%.*]], i8* align 1 [[STR]], i32 [[LENINC]], i1 false)
> > +; CHECK-NEXT: [[STRCPY:%.*]] = call i8* @strcpy(i8* nonnull
> dereferenceable(1) [[DST:%.*]], i8* nonnull dereferenceable(1) [[STR:%.*]])
> > ; CHECK-NEXT: ret void
> > ;
> > ; CHECK-IPRINTF-LABEL: @test_simplify5(
> > -; CHECK-IPRINTF-NEXT: [[STRLEN:%.*]] = call i32 @strlen(i8* nonnull
> dereferenceable(1) [[STR:%.*]])
> > -; CHECK-IPRINTF-NEXT: [[LENINC:%.*]] = add i32 [[STRLEN]], 1
> > -; CHECK-IPRINTF-NEXT: call void @llvm.memcpy.p0i8.p0i8.i32(i8* align
> 1 [[DST:%.*]], i8* align 1 [[STR]], i32 [[LENINC]], i1 false)
> > +; CHECK-IPRINTF-NEXT: [[STRCPY:%.*]] = call i8* @strcpy(i8* nonnull
> dereferenceable(1) [[DST:%.*]], i8* nonnull dereferenceable(1) [[STR:%.*]])
> > ; CHECK-IPRINTF-NEXT: ret void
> > ;
> > %fmt = getelementptr [3 x i8], [3 x i8]* @percent_s, i32 0, i32 0
> >
> >
> >
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