Displaying 20 results from an estimated 153 matches for "dso_local".
2020 Jan 22
4
Inlining + CSE + restrict pointers == funtimes
...this
down to the following failure (see https://godbolt.org/z/-mdjPV):
int called(int* __restrict__ a, int* b, int* c) {
return *a + *b + *c;
}
int foo(int * x, int * y) {
return *x + *y + called(x, x, y);
}
int bar(int * x, int * y) {
return called(x, x, y) + *x + *y;
}
Which becomes:
define dso_local i32 @called(i32* noalias nocapture readonly %0, i32*
nocapture readonly %1, i32* nocapture readonly %2) local_unnamed_addr #0 !
dbg !7 {
%4 = load i32, i32* %0, align 4, !dbg !19, !tbaa !20
%5 = load i32, i32* %1, align 4, !dbg !24, !tbaa !20
%6 = add nsw i32 %5, %4, !dbg !25
%7 = load i32, i32* %2...
2020 Jul 06
3
Question about basic-aa's assumptions
...0x565ee028
pc : 0x565ee028
c : 0x565ee024
*pc: 0x565ee024
Basically, I would have liked if basic-aa said ppc and pc are may-aliased
to start with for this kind of usage. This is how the globals look like.
The second one: "ppc" has "pc" on the right hand side.
@pc = common dso_local global [4 x i8*] zeroinitializer, align 4, !dbg !0
@ppc = dso_local global i8** getelementptr inbounds ([4 x i8*], [4 x i8*]*
@pc, i32 0, i32 0), align 4, !dbg !6
Best regards,
Ram
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2019 Mar 25
2
[IndVars] Rewriting exit value of SCEV add expressions
...gressed here, because before rL346397 we would rewrite the exit value of SCEV add expression even if there is hard use inside the loop.
Here is the reproducer:
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"
@c = external dso_local local_unnamed_addr global i32, align 4
@a = external dso_local local_unnamed_addr global i32*, align 8
@b = external dso_local local_unnamed_addr global i32, align 4
@d = external dso_local local_unnamed_addr global i32, align 4
define i32 @foo(){
entry:
%0 = load i32*, i32** @a, align 8
%.pre...
2020 Jun 28
2
__restirct ignored when including headers like <cmath>
...es __restirct when I
include some standard headers.
For example, this code:
void vec_add(int* __restrict a,
int* __restrict b,
int n) {
#pragma unroll 4
for(int i=0; i<n; ++i) {
a[i] += b[i];
}
}
results in:
; Function Attrs: nofree norecurse nounwind
define dso_local void @_Z7vec_addPiS_i(i32* noalias nocapture %a, i32*
noalias nocapture readonly %b, i32 %n) local_unnam
ed_addr #0 {
entry:
.
.
...
(note the noaliass before function arguments).
But this code:
#include <cmath>
void vec_add(int* __restrict a,
int* __restrict b,...
2020 May 31
2
Question about Constant expressions
...dds it as a separate instruction, but it is
rolled into one call instruction in the .bc output.
I am just curious as to why it is done this way.
#include <stdint.h>
#include <stdio.h>
int test21(void);
int test21(void) {
printf("Hello1\n");
return 0;
}
define dso_local i32 @test21() #0 {
%1 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([8 x
i8], [8 x i8]* @.str, i64 0, i64 0))
ret i32 0
}
2019 Aug 31
3
Usage of the jumptable attribute
...target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"
@.str = private unnamed_addr constant [12 x i8] c"Hello World\00",
align 1
; Function Attrs: jumptable noinline nounwind optnone uwtable
define dso_local void @foo() unnamed_addr #0 {
%1 = call i32 @puts(i8* getelementptr inbounds ([12 x i8], [12 x
i8]* @.str, i32 0, i32 0))
ret void
}
declare dso_local i32 @puts(i8*) #1
; Function Attrs: jumptable noinline nounwind optnone uwtable
define dso_local i32 @main() un...
2020 Jan 11
2
[RFC][SDAG] Convert build_vector of ops on extractelts into ops on input vectors
...on I say that is
that the inputs are vectors and the output is also a vector - we just
perform the operation on extracted elements rather than on the input
vectors themselves.
In the PR you linked, there is an example that shows the difference
(simplified to <2 x double> for brevity):
define dso_local <2 x double> @test(i64 %a, i64 %b) {
entry:
%conv = uitofp i64 %a to double
%conv1 = uitofp i64 %b to double
%vecinit = insertelement <2 x double> undef, double %conv, i32 0
%vecinit2 = insertelement <2 x double> %vecinit, double %conv1, i32 1
ret <2 x double> %vec...
2020 May 07
2
Emitting a local alias
...want to be able to place
_ZTVSt13bad_exception in .rodata instead of .data.rel.ro which requires
that the object does not need a relocation.
According to `Constant::needsRelocation()`, a reloc isn't needed if the
offset I'm taking (.long symbol_A - symbol_B) contains symbols that are
both dso_local. I can guarantee that `symbol_A` will be, but `symbol_B`
needs to be a global with default visibility. My solution around this is to
emit a local alias, but the issue is that with optimizations (-O3), the
latter snippet seems to "resolve" the aliases and instead replaces them
with my alia...
2019 Nov 28
2
Question on TBAA and optimization
...;Aptr" and "Bptr" will not alias each other in both
the functions.
TBAA is able to figure that out in the case of "foo2". Hence it could
propagate the value "10" directly for return in "foo2".
--IR snippet ---
; Function Attrs: nounwind uwtable
define dso_local i32 @foo1(%struct.A* %Aptr, %struct.B* %Bptr)
local_unnamed_addr #0 {
entry:
%b1 = getelementptr inbounds %struct.A, %struct.A* %Aptr, i64 0, i32 1,
i32 0
store i32 10, i32* %b1, align 4, !tbaa !2
%b11 = getelementptr inbounds %struct.B, %struct.B* %Bptr, i64 0, i32 0
store i32 11, i32* %b1...
2017 Jun 14
2
Refining which symbols are preemptable with lto
As a follow up to https://reviews.llvm.org/D20217 I would like to use
lto/thinlto to refine when a symbol is marked as local/preemptable.
I'm not very familiar with lto though so would appreciate some
guidance about how best to go about this.
Regards
Sean Fertile
2020 May 14
2
Sancov guard semantics for usage between comdats
...nitize-coverage=trace-pc-guard
/tmp/test.cpp -c -O1` generates sancov guards (__sancov_gen_.X) that are
used outside of their comdat group due to inlining:
```
@__sancov_gen_.1 = private global [3 x i32] zeroinitializer, section
"__sancov_guards", comdat($_ZN3Foo10inline_fooEv)
define dso_local i32 @_ZN3Foo10public_fooEv(%struct.Foo* %0)
local_unnamed_addr #0 comdat align 2 {
call void @__sanitizer_cov_trace_pc_guard(i32* getelementptr inbounds ([3
x i32], [3 x i32]* @__sancov_gen_, i64 0, i64 0))
call void asm sideeffect "", ""() #4
; This is from inlining Fo...
2020 Jun 12
3
Why doesn't this `and` get eliminated
define dso_local i32 @f(i32 %0) {
%2 = and i32 %0, 7
%3 = icmp eq i32 %2, 7
%4 = zext i1 %3 to i32
ret i32 %4
}
I thought instcombine would remove it. It doesn't and nothing else does either. LLVM Version is 10.0.0.
/Riyaz
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2020 Jan 11
2
[RFC][SDAG] Convert build_vector of ops on extractelts into ops on input vectors
...output is also a vector - we just
>> perform the operation on extracted elements rather than on the input
>> vectors themselves.
>>
>> In the PR you linked, there is an example that shows the difference
>> (simplified to <2 x double> for brevity):
>> define dso_local <2 x double> @test(i64 %a, i64 %b) {
>> entry:
>> %conv = uitofp i64 %a to double
>> %conv1 = uitofp i64 %b to double
>> %vecinit = insertelement <2 x double> undef, double %conv, i32 0
>> %vecinit2 = insertelement <2 x double> %vecinit, doubl...
2018 Aug 11
4
Need help in understanding llvm optimization
Hi,
I have below code in C -
int main() {
double x,y;
x = 1e16;
y = (x + 1) - x;
printf("y:%e\n", y);
return 0;
}
llvm bitcode looks like this for this function -
; Function Attrs: nounwind uwtable
define dso_local i32 @main() local_unnamed_addr #0 {
entry:
%call = tail call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([4 x
i8], [4 x i8]* @.str, i64 0, i64 0), double 0.000000e+00)
ret i32 0
}
I am not able to understand how addition and subtraction are performed in
this code. There is no fadd o...
2019 Jun 30
2
Information Loss of Array Type in Function Interface in IR Generated by Clang
...,
Thanks for your prompt reply!
Sure, I can implement a AST visitor to go through the AST to get the information but I just wonder whether there is any other way to let Clang do so.
What I am considering is how to let the generated IR looks like below, which some tools realize:
define dso_local i32 @_Z1fPii([51 x i32]* %A, i32 %x) local_unnamed_addr #0 !dbg !7 {
entry:
...
}
Best regards,
------------------------------------------
Tingyuan LIANG
MPhil Student
Department of Electronic and Computer Engineering
The Hong Kong University of Science and Technology
_____________________________...
2018 Jul 28
2
ThinLTO Bug ?
...b.o b.ll
~/llvm/build-debug/bin/llvm-lto2 run -o c a.o b.o -r a.o,c,px -r
b.o,a,px -r b.o,b,px -r a.o,gv -r b.o,gv
[~/thinltobug]$ cat a.ll
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"
%struct.TA = type {}
@gv = dso_local global %struct.TA * zeroinitializer
define i32 @c() !dbg !6 {
bitcast %struct.TA ** @gv to i8*
unreachable
}
!llvm.module.flags = !{!0, !1}
!llvm.dbg.cu = !{!2}
!0 = !{i32 2, !"Debug Info Version", i32 3}
!1 = !{i32 1, !"ThinLTO", i32 0}
!2 = distinct !DICompile...
2018 Jul 30
2
ThinLTO Bug ?
...>
> >
> > [~/thinltobug]$ cat a.ll
> >
> > target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
> >
> > target triple = "x86_64-unknown-linux-gnu"
> >
> > %struct.TA = type {}
> >
> >
> >
> > @gv = dso_local global %struct.TA * zeroinitializer
> >
> > define i32 @c() !dbg !6 {
> >
> > bitcast %struct.TA ** @gv to i8*
> >
> > unreachable
> >
> > }
> >
> >
> >
> >
> >
> > !llvm.module.flags = !{!0, !1}
> >
>...
2018 Apr 15
2
LLVM Alias Analysis (Load and store from same address is not showed up in same set)
...quot;e-m:e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"
@fp = internal global i32 ()* null, align 8
@.str = private unnamed_addr constant [13 x i8] c"hello world\0A\00", align 1
; Function Attrs: noinline nounwind optnone uwtable
define dso_local void @ind_call(i32 ()* %compr) #0 {
entry:
%compr.addr = alloca i32 ()*, align 8
store i32 ()* %compr, i32 ()** %compr.addr, align 8
%0 = load i32 ()*, i32 ()** %compr.addr, align 8
store i32 ()* %0, i32 ()** @fp, align 8
%1 = load i32 ()*, i32 ()** @fp, align 8
%call = call i32...
2019 Jun 30
2
Information Loss of Array Type in Function Interface in IR Generated by Clang
...Clang command I used is :
clang -O1 -emit-llvm -S -g tmp.cc -o tmp.bc
Thanks in advance for your time and suggestion! ^_^
C source code:
int f ( int A[51], int x)
{
return A[x];
}
===========================
generated IR:
; Function Attrs: norecurse nounwind readonly uwtable
define dso_local i32 @_Z1fPii(i32* nocapture readonly %A, i32 %x) local_unnamed_addr #0 !dbg !7 {
entry:
call void @llvm.dbg.value(metadata i32* %A, metadata !13, metadata !DIExpression()), !dbg !15
call void @llvm.dbg.value(metadata i32 %x, metadata !14, metadata !DIExpression()), !dbg !16
%idxprom = sext i3...
2019 Dec 10
2
TypePromoteFloat loses intermediate rounding operations
For the following C code
__fp16 x, y, z, w;
void foo() {
x = y + z;
x = x + w;
}
clang produces IR that extends each operand to float and then truncates to
half before assigning to x. Like this
define dso_local void @foo() #0 !dbg !18 {
%1 = load half, half* @y, align 2, !dbg !21
%2 = fpext half %1 to float, !dbg !21
%3 = load half, half* @z, align 2, !dbg !22
%4 = fpext half %3 to float, !dbg !22
%5 = fadd float %2, %4, !dbg !23
%6 = fptrunc float %5 to half, !dbg !21
store half %6, half* @x, align 2, !d...