https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71414
Raphael C changed:
What|Removed |Added
CC||drraph at gmail dot com
--- Comment #12
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79201
--- Comment #5 from Raphael C ---
I can confirm you now get
f:
mov eax, 1
ret
with gcc 8 onwards.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79185
--- Comment #17 from Raphael C ---
Tested in gcc 11.1 with -O2
ai(__int128, __int128):
mov r9, rdi
mov rax, rdx
mov r8, rsi
mov rdx, rcx
add rax, r9
adc rdx, r8
ret
: c
Assignee: unassigned at gcc dot gnu.org
Reporter: drraph at gmail dot com
Target Milestone: ---
This report has two parts. The first is about complex float division and the
second about complex double division.
--- Part 1 ---
Consider:
#include
complex float f(complex
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=46186
Raphael C changed:
What|Removed |Added
CC||drraph at gmail dot com
--- Comment #26
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80852
--- Comment #2 from Raphael C ---
You are quite right. This code shows the same issue:
int foo(int num) {
int a = 0;
for (int x = 0; x < num; x+=2) {
a += x;
}
return a;
}
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: drraph at gmail dot com
Target Milestone: ---
Consider this (slightly odd) code:
int foo(int num) {
int a = 0;
for (int x = 0; x < num; x+=2) {
if (!(x % 2)) {
a +
Assignee: unassigned at gcc dot gnu.org
Reporter: drraph at gmail dot com
Target Milestone: ---
Consider:
double f(double x[]) {
float p = 1.0;
for (int i = 0; i < 16; i++)
p += x[i];
return p;
}
gcc with -O3 -march=core-avx2 -ffast-math gives:
f:
vmovsd xmm0, QWORD
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: drraph at gmail dot com
Target Milestone: ---
Consider:
#include
complex double f(complex double x[]) {
complex float p = 1.0;
for (int i = 0; i < 100; i++)
p = x[i];
return p;
}
This compiles using
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: drraph at gmail dot com
Target Milestone: ---
Consider:
float f(float x[], float y[]) {
float p = 0;
for (int i = 0; i <64; i++)
p += x[i] * y[i];
return p;
}
Using gcc 7 (snaps
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79460
--- Comment #1 from Raphael C ---
After some experimentation (also carried out by Hagen von Eitzen), it seems
that any limit of at least 72 which is also a multiple of 4 causes the same
optimisation problem. That is the loop is *not* optimised
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: drraph at gmail dot com
Target Milestone: ---
Consider:
float f(float x[]) {
float p = 1.0;
for (int i = 0; i < 202; i++)
p += 1;
retur
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79359
--- Comment #2 from Raphael C ---
As an additional data point in relation to Part 2 (that is without
-ffast-math). In gcc 7 -O3 -ffinite-math-only gives
f:
movqQWORD PTR [rsp-16], xmm0
movss xmm3, DWORD PTR [rsp-12]
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79359
--- Comment #1 from Raphael C ---
In case it's of any help, here is an explanation of the assembly that ICC gives
with -fp-model strict.
R = real and C = complex. Here "x" just means don't know or unused.
We start with xmm0 = {x, x, C, R}.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79357
--- Comment #1 from Raphael C ---
I omitted
.L_2il0floatpacket.1:
.long 0x4000,0x4000,0x,0x
.long 0x4000,0x
from the assembly. In other words it just multiplies by 2.0f.
: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: drraph at gmail dot com
Target Milestone: ---
Consider:
#include
complex float f(complex float x) {
return x*x;
}
This PR has two parts.
Part 1.
In gcc 7 with -Ofast
: c
Assignee: unassigned at gcc dot gnu.org
Reporter: drraph at gmail dot com
Target Milestone: ---
Consider the following code:
#include
complex float f(complex float x) {
return 2*x;
}
gcc with -O3 -march=core-avx2 gives:
f:
vmovq QWORD PTR [rsp-8], xmm0
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: drraph at gmail dot com
Target Milestone: ---
Consider this code:
#include
complex float f(complex float x[]) {
complex float p = 1.0;
for (int i = 0; i < 32; i++)
p += x[i];
retur
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: drraph at gmail dot com
Target Milestone: ---
Consider this code:
int f(int n) {
int i,j=0;
for (i = 0; i < 32; i++) {
j = __builtin_ffs(i);
}
return j;
}
With gcc -O3 you get
: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: drraph at gmail dot com
Target Milestone: ---
Consider this code:
__int128_t ai (__int128_t x, __int128_t y) {
return x + y;
}
In gcc 4.8.5, clang and icc using -O2
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: drraph at gmail dot com
Target Milestone: ---
Consider this simple piece of code.
#include
complex float f(complex float x[]) {
complex float p = 1.0;
for (int i = 0; i < 128
21 matches
Mail list logo
