On Fri, Feb 07, 2020 at 10:57:22AM +0000, JonY wrote:
> >> Is this patch testing still required? I just got back from traveling.
> >
> > Yes, our reading of the MS ABI docs show that xmm16-31 are to be call used
> > (not preserved over calls), while in gcc they are currently handled as
> > preserved across the calls.
The other parts are I guess mainly about SEH. Consider e.g.
void
foo (void)
{
register double x __asm ("xmm14");
register double y __asm ("xmm18");
asm ("" : "=x" (x));
asm ("" : "=v" (y));
x += y;
y += x;
asm ("" : : "x" (x));
asm ("" : : "v" (y));
}
looking at cross-compiler output, with -O2 -mavx512f this emits
.file "abcdeq.c"
.text
.align 16
.globl foo
.def foo; .scl 2; .type 32; .endef
.seh_proc foo
foo:
subq $40, %rsp
.seh_stackalloc 40
vmovaps %xmm14, (%rsp)
.seh_savexmm %xmm14, 0
vmovaps %xmm18, 16(%rsp)
.seh_savexmm %xmm18, 16
.seh_endprologue
vaddsd %xmm18, %xmm14, %xmm14
vaddsd %xmm18, %xmm14, %xmm18
vmovaps (%rsp), %xmm14
vmovaps 16(%rsp), %xmm18
addq $40, %rsp
ret
.seh_endproc
.ident "GCC: (GNU) 10.0.1 20200207 (experimental)"
Does whatever assembler mingw64 uses even assemble this (I mean the
.seh_savexmm %xmm16, 16 could be problematic)?
I can find e.g.
https://stackoverflow.com/questions/43152633/invalid-register-for-seh-savexmm-in-cygwin/43210527
which then links to
https://gcc.gnu.org/PR65782
So, I'd say we want to add PR target/65782 to the ChangeLog entry in the
patch, and likely add a testcase like the above, so like below?
Have you tested the earlier version of the patch on mingw64 or cygwin?
If yes, can you just test the testcase from the following patch, without and
with the i386.h part and verify it FAILs without and PASSes with it?
Just make check-gcc RUNTESTFLAGS=i386.exp=pr65782.c should do?
If not, can you please test the whole patch?
2020-02-07 Uroš Bizjak <ubiz...@gmail.com>
Jakub Jelinek <ja...@redhat.com>
PR target/65782
* config/i386/config/i386/i386.h (CALL_USED_REGISTERS): Make
xmm16-xmm31 call-used even in 64-bit ms-abi.
* gcc.target/i386/pr65782.c: New test.
--- gcc/config/i386/config/i386/i386.h.jj 2020-01-22 10:19:24.199221986
+0100
+++ gcc/config/i386/config/i386/i386.h 2020-02-04 12:09:12.338341003 +0100
@@ -1128,9 +1128,9 @@ extern const char *host_detect_local_cpu
/*xmm8,xmm9,xmm10,xmm11,xmm12,xmm13,xmm14,xmm15*/ \
6, 6, 6, 6, 6, 6, 6, 6, \
/*xmm16,xmm17,xmm18,xmm19,xmm20,xmm21,xmm22,xmm23*/ \
- 6, 6, 6, 6, 6, 6, 6, 6, \
+ 1, 1, 1, 1, 1, 1, 1, 1, \
/*xmm24,xmm25,xmm26,xmm27,xmm28,xmm29,xmm30,xmm31*/ \
- 6, 6, 6, 6, 6, 6, 6, 6, \
+ 1, 1, 1, 1, 1, 1, 1, 1, \
/* k0, k1, k2, k3, k4, k5, k6, k7*/ \
1, 1, 1, 1, 1, 1, 1, 1 }
--- gcc/testsuite/gcc.target/i386/pr65782.c.jj 2020-02-07 12:21:09.472819018
+0100
+++ gcc/testsuite/gcc.target/i386/pr65782.c 2020-02-07 12:24:06.820154495
+0100
@@ -0,0 +1,16 @@
+/* PR target/65782 */
+/* { dg-do assemble { target { avx512vl && { ! ia32 } } } } */
+/* { dg-options "-O2 -mavx512vl" } */
+
+void
+foo (void)
+{
+ register double x __asm ("xmm14");
+ register double y __asm ("xmm18");
+ asm ("" : "=x" (x));
+ asm ("" : "=v" (y));
+ x += y;
+ y += x;
+ asm ("" : : "x" (x));
+ asm ("" : : "v" (y));
+}
Jakub
