[Bug target/110273] [12/13/14 Regression] i686-w64-mingw32 with -mavx512f generates AVX instructions without stack alignment
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110273 Jeffrey A. Law changed: What|Removed |Added Priority|P3 |P2 CC||law at gcc dot gnu.org
[Bug target/110273] [12/13/14 Regression] i686-w64-mingw32 with -mavx512f generates AVX instructions without stack alignment
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110273 --- Comment #14 from H.J. Lu --- (In reply to Zeb Figura from comment #13) > (In reply to Sam James from comment #11) > > (In reply to Jens-Hanno Schwalm from comment #10) > > > Hi, i think we found a very-similar issue in darktable code, you might > > > look > > > at > > > > > > https://github.com/darktable-org/darktable/pull/15742 > > > > > > > If you're hitting this on another target than i686-w64-mingw32, please file > > a new bug. We can always mark it as a dupe if it turns out to be, although I > > suspect it isn't here. > > FWIW, I think the relevant part of i686-w64-ming32 is actually just > STACK_REALIGN_DEFAULT. I can reproduce the same lack of alignment with > "-mstackrealign -mavx512 -O2" with i386-linux-gnu, whereas "-mstackrealign > -mavx2 -O2" does align the stack. [-O2 is necessary here otherwise gcc will > just use vmovdqu and not bother aligning the stack. No idea what the more > targeted optimization is.] > For the attached testcase here, GCC 13.2 generates: [hjl@gnu-cfl-3 tmp]$ gcc -S -mstackrealign -mavx512f -O2 -m32 x.c [hjl@gnu-cfl-3 tmp]$ head -20 x.s .file "x.c" .text .p2align 4 .globl ddraw7_GetCaps .type ddraw7_GetCaps, @function ddraw7_GetCaps: .LFB0: .cfi_startproc leal4(%esp), %ecx .cfi_def_cfa 1, 0 andl$-16, %esp < Stack realignment. vpxor %xmm0, %xmm0, %xmm0 xorl%eax, %eax pushl -4(%ecx) pushl %ebp movl%esp, %ebp .cfi_escape 0x10,0x5,0x2,0x75,0 pushl %edi pushl %ecx .cfi_escape 0xf,0x3,0x75,0x78,0x6 [hjl@gnu-cfl-3 tmp]$ It works for me. Please file a separate bug if-mstackrealign -mavx512f -O2 doesn't work for you on Linux.
[Bug target/110273] [12/13/14 Regression] i686-w64-mingw32 with -mavx512f generates AVX instructions without stack alignment
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110273 --- Comment #13 from Zeb Figura --- (In reply to Sam James from comment #11) > (In reply to Jens-Hanno Schwalm from comment #10) > > Hi, i think we found a very-similar issue in darktable code, you might look > > at > > > > https://github.com/darktable-org/darktable/pull/15742 > > > > If you're hitting this on another target than i686-w64-mingw32, please file > a new bug. We can always mark it as a dupe if it turns out to be, although I > suspect it isn't here. FWIW, I think the relevant part of i686-w64-ming32 is actually just STACK_REALIGN_DEFAULT. I can reproduce the same lack of alignment with "-mstackrealign -mavx512 -O2" with i386-linux-gnu, whereas "-mstackrealign -mavx2 -O2" does align the stack. [-O2 is necessary here otherwise gcc will just use vmovdqu and not bother aligning the stack. No idea what the more targeted optimization is.] I'd assume this is a bug with -mstackrealign, but I also don't understand what the intended purpose of -mstackrealign is. How does it differ from -mincoming-stack-boundary=2 or -mpreferred-stack-boundary=2?
[Bug target/110273] [12/13/14 Regression] i686-w64-mingw32 with -mavx512f generates AVX instructions without stack alignment
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110273 --- Comment #12 from Andrew Pinski --- (In reply to Sam James from comment #11) > (In reply to Jens-Hanno Schwalm from comment #10) > > Hi, i think we found a very-similar issue in darktable code, you might look > > at > > > > https://github.com/darktable-org/darktable/pull/15742 > > > > If you're hitting this on another target than i686-w64-mingw32, please file > a new bug. We can always mark it as a dupe if it turns out to be, although I > suspect it isn't here. Though it might be PR 110027 ...
[Bug target/110273] [12/13/14 Regression] i686-w64-mingw32 with -mavx512f generates AVX instructions without stack alignment
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110273 --- Comment #11 from Sam James --- (In reply to Jens-Hanno Schwalm from comment #10) > Hi, i think we found a very-similar issue in darktable code, you might look > at > > https://github.com/darktable-org/darktable/pull/15742 > If you're hitting this on another target than i686-w64-mingw32, please file a new bug. We can always mark it as a dupe if it turns out to be, although I suspect it isn't here.
[Bug target/110273] [12/13/14 Regression] i686-w64-mingw32 with -mavx512f generates AVX instructions without stack alignment
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110273
Jens-Hanno Schwalm changed:
What|Removed |Added
CC||ha...@schwalm-bremen.de
--- Comment #10 from Jens-Hanno Schwalm ---
Hi, i think we found a very-similar issue in darktable code, you might look at
https://github.com/darktable-org/darktable/pull/15742
In short
- reported with gcc 13.2.1, -march=znver4 or using -fvect-cost-model=dynamic
The code in question was
```
typedef struct dt_draw_curve_t
{
CurveData c;
CurveSample csample;
} dt_draw_curve_t;
static inline void dt_draw_curve_set_point(dt_draw_curve_t *c,
const int num,
const float x,
const float y)
{
c->c.m_anchors[num].x = x;
c->c.m_anchors[num].y = y;
}
static void _generate_curve_lut( ...)
{
...
dt_iop_rgbcurve_node_t curve_nodes[3][20];
...
for(int k = 0; k < d->params.curve_num_nodes[ch]; k++)
dt_draw_curve_set_point(d->curve[ch], k,
curve_nodes[ch][k].x,
curve_nodes[ch][k].y);
...
}
```
The relevant point here was:
even if the curve_nodes are not aligned64 the compiled code looked like
lea (%rcx, %rbx,1), %rdi
vmoaps -0x220(%rbp, %rdi,8), %ymm2
vmoups %ymm2, 0x18(%r15,%rcx,8)
forcing an alignment64 on curve_nodes fixed the problem
reporting this as one of darktable devs - no compiler expert at all - and never
reported here before. Yet this seems a bug and possibly the same are originally
reported here.
[Bug target/110273] [12/13/14 Regression] i686-w64-mingw32 with -mavx512f generates AVX instructions without stack alignment
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110273 --- Comment #9 from Sam James --- Yes - primarily from znver4 users who build with -march=native (or -march=znver4).
[Bug target/110273] [12/13/14 Regression] i686-w64-mingw32 with -mavx512f generates AVX instructions without stack alignment
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110273 --- Comment #8 from Alexander Monakov --- (In reply to Sam James from comment #7) > We keep getting quite a few reports of this downstream. Of this mingw32 stack realignment issue specifically, i.e. Wine breakage when AVX512 is enabled via CFLAGS?
[Bug target/110273] [12/13/14 Regression] i686-w64-mingw32 with -mavx512f generates AVX instructions without stack alignment
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110273 --- Comment #7 from Sam James --- We keep getting quite a few reports of this downstream.
[Bug target/110273] [12/13/14 Regression] i686-w64-mingw32 with -mavx512f generates AVX instructions without stack alignment
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110273 Richard Biener changed: What|Removed |Added Target Milestone|--- |12.4
[Bug target/110273] [12/13/14 Regression] i686-w64-mingw32 with -mavx512f generates AVX instructions without stack alignment
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110273 --- Comment #6 from Alexander Monakov --- Huh? Just compile the supplied testcases without avx512, you'll see proper stack realignment.
[Bug target/110273] [12/13/14 Regression] i686-w64-mingw32 with -mavx512f generates AVX instructions without stack alignment
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110273 --- Comment #5 from H.J. Lu --- GCC doesn't align stack for Windows. As a workaround, one can pass -muse-unaligned-vector-move to newer assembler.
