Date: Fri, 27 Nov 1998 19:56:32 -0500 (EST) From: "John S. Dyson" <dyson@iquest.net> To: current@FreeBSD.ORG Subject: Fix for incorrect clobbers in asm's Message-ID: <199811280056.TAA03374@y.dyson.net>
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Note that the specification for clobbers in inline asm's
on GCC hasn't always been clear. The attached patches correct
the clobbers in the inline asms for current.
Specifically, it is totally incorrect to clobber any of the input
or output operands. The workaround is to indicate that the clobbered
registers are output operands, with no subsequent usage. It might
be counter-intuitive, but is the suggested solution to the problem.
--
John | Never try to teach a pig to sing,
dyson@iquest.net | it makes one look stupid
jdyson@nc.com | and it irritates the pig.
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Index: i386/i386/identcpu.c
===================================================================
RCS file: /local/home/ncvs/src/sys/i386/i386/identcpu.c,v
retrieving revision 1.52
diff -C1 -r1.52 identcpu.c
*** identcpu.c 1998/10/06 13:16:23 1.52
--- identcpu.c 1998/11/28 00:49:10
***************
*** 106,107 ****
--- 106,108 ----
{
+ int nax;
__asm __volatile(
***************
*** 112,116 ****
"movl %%edx, (12)(%%esi);"
! :
: "a" (ax), "S" (p)
! : "ax", "bx", "cx", "dx"
);
--- 113,117 ----
"movl %%edx, (12)(%%esi);"
! : "=a"(nax)
: "a" (ax), "S" (p)
! : "bx", "cx", "dx"
);
Index: i386/include/cpufunc.h
===================================================================
RCS file: /local/home/ncvs/src/sys/i386/include/cpufunc.h,v
retrieving revision 1.81
diff -C1 -r1.81 cpufunc.h
*** cpufunc.h 1998/08/17 08:57:05 1.81
--- cpufunc.h 1998/11/28 00:46:45
***************
*** 192,196 ****
{
__asm __volatile("cld; rep; insb"
! : : "d" (port), "D" (addr), "c" (cnt)
! : "di", "cx", "memory");
}
--- 192,198 ----
{
+ int ndi, ncx;
__asm __volatile("cld; rep; insb"
! : "=D"(ndi), "=c"(ncx)
! : "d" (port), "D" (addr), "c" (cnt)
! : "memory");
}
***************
*** 200,204 ****
{
__asm __volatile("cld; rep; insw"
! : : "d" (port), "D" (addr), "c" (cnt)
! : "di", "cx", "memory");
}
--- 202,208 ----
{
+ int ndi, ncx;
__asm __volatile("cld; rep; insw"
! : "=D"(ndi), "=c"(ncx)
! : "d" (port), "D" (addr), "c" (cnt)
! : "memory");
}
***************
*** 208,212 ****
{
__asm __volatile("cld; rep; insl"
! : : "d" (port), "D" (addr), "c" (cnt)
! : "di", "cx", "memory");
}
--- 212,218 ----
{
+ int ndi, ncx;
__asm __volatile("cld; rep; insl"
! : "=D"(ndi), "=c"(ncx)
! : "d" (port), "D" (addr), "c" (cnt)
! : "memory");
}
***************
*** 323,327 ****
{
__asm __volatile("cld; rep; outsb"
! : : "d" (port), "S" (addr), "c" (cnt)
! : "si", "cx");
}
--- 329,334 ----
{
+ int nsi, ncx;
__asm __volatile("cld; rep; outsb"
! : "=S"(nsi), "=c"(ncx)
! : "d" (port), "S" (addr), "c" (cnt));
}
***************
*** 331,335 ****
{
__asm __volatile("cld; rep; outsw"
! : : "d" (port), "S" (addr), "c" (cnt)
! : "si", "cx");
}
--- 338,343 ----
{
+ int nsi, ncx;
__asm __volatile("cld; rep; outsw"
! : "=S"(nsi), "=c"(ncx)
! : "d" (port), "S" (addr), "c" (cnt));
}
***************
*** 339,343 ****
{
__asm __volatile("cld; rep; outsl"
! : : "d" (port), "S" (addr), "c" (cnt)
! : "si", "cx");
}
--- 347,352 ----
{
+ int nsi, ncx;
__asm __volatile("cld; rep; outsl"
! : "=S"(nsi), "=c"(ncx)
! : "d" (port), "S" (addr), "c" (cnt));
}
Index: i386/isa/sound/audio.c
===================================================================
RCS file: /local/home/ncvs/src/sys/i386/isa/sound/audio.c,v
retrieving revision 1.19
diff -C1 -r1.19 audio.c
*** audio.c 1998/07/15 11:47:58 1.19
--- audio.c 1998/11/28 00:50:36
***************
*** 167,168 ****
--- 167,169 ----
{
+ int nbx, ncx, ndi, nsi;
if (n > 0) {
***************
*** 172,176 ****
"stosb\n\t"
! "loop 1b\n\t":
:"b"(table), "c"(n), "D"(buff), "S"(buff)
! :"bx", "cx", "di", "si", "ax");
}
--- 173,178 ----
"stosb\n\t"
! "loop 1b\n\t"
! :"=b"(nbx), "=c"(ncx), "=D" (ndi), "=S" (nsi)
:"b"(table), "c"(n), "D"(buff), "S"(buff)
! :"ax");
}
--ELM912214592-3366-0_--
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