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Revert "[SLC] sprintf(dst, "%s", str) -> strcpy(dst, str)" 

This reverts commit ab9fc8bae8.

Incorrect transformation if the result is used.
Causes breakages, e.g.
http://green.lab.llvm.org/green/job/test-suite-verify-machineinstrs-x86_64-O3/8193/
This commit is contained in:
Arthur Eubanks 2020-08-13 21:05:03 -07:00
parent 800f0eda5b
commit 48cd5b72b1
3 changed files with 21 additions and 12 deletions
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14
llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
View File

@ -2487,11 +2487,21 @@ Value *LibCallSimplifier::optimizeSPrintFString(CallInst *CI,
}
if (FormatStr[1] == 's') {
// sprintf(dest, "%s", str) -> strcpy(dest, str)
// sprintf(dest, "%s", str) -> llvm.memcpy(align 1 dest, align 1 str,
// strlen(str)+1)
if (!CI->getArgOperand(2)->getType()->isPointerTy())
return nullptr;
return emitStrCpy(CI->getArgOperand(0), CI->getArgOperand(2), B, TLI);
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 nullptr;
}

9
llvm/test/Transforms/InstCombine/2010-05-30-memcpy-Struct.ll
View File

@ -1,4 +1,3 @@
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt -instcombine -S < %s | FileCheck %s
; PR7265
@ -10,14 +9,10 @@ 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
}

10
llvm/test/Transforms/InstCombine/sprintf-1.ll
View File

@ -81,15 +81,19 @@ define void @test_simplify4(i8* %dst) {
ret void
}
; Check sprintf(dst, "%s", str) -> strcpy(dst, str)
; Check sprintf(dst, "%s", str) -> llvm.memcpy(dest, str, strlen(str) + 1, 1).
define void @test_simplify5(i8* %dst, i8* %str) {
; CHECK-LABEL: @test_simplify5(
; CHECK-NEXT: [[STRCPY:%.*]] = call i8* @strcpy(i8* nonnull dereferenceable(1) [[DST:%.*]], i8* nonnull dereferenceable(1) [[STR:%.*]])
; 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: ret void
;
; CHECK-IPRINTF-LABEL: @test_simplify5(
; CHECK-IPRINTF-NEXT: [[STRCPY:%.*]] = call i8* @strcpy(i8* nonnull dereferenceable(1) [[DST:%.*]], i8* nonnull dereferenceable(1) [[STR:%.*]])
; 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: ret void
;
%fmt = getelementptr [3 x i8], [3 x i8]* @percent_s, i32 0, i32 0