This is the mail archive of the fortran@gcc.gnu.org mailing list for the GNU Fortran project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: Use i386/crtfastmath.c on Solaris 2/x86


Richard Henderson <rth@redhat.com> writes:

> On 06/01/2011 07:51 AM, Rainer Orth wrote:
>> +  /* Set PC to the instruction after the faulting one to skip over it,
>> +     otherwise we enter an infinite loop.  4 is the size of the stmxcsr
>> +     instruction.  */
> ...
>> +      /* We need a single SSE instruction here so the handler can safely skip
>> +	 over it.  */
>> +      __asm__ volatile ("movss %xmm2,%xmm1");
>
> The comment referencing stmxcsr doesn't match the movss code.
> It's still a 4 byte opcode, so the code still works.
>
> I do wonder if using "movaps %xmm0,%xmm0" might be cleaner,
> to avoid clobbering a register, even if that register is
> surely dead anyway.  That's a 3 byte opcode though, so the
> handler would need updating.

Here's what I installed after regtesting completed on
i386-pc-solaris2.{8, 11}.

Thanks.
	Rainer


2011-06-02  Richard Henderson  <rth@redhat.com>
	    Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>

	gcc:
	* config/i386/crtfastmath.c [!__x86_64__ && __sun__ && __svr4__]
	(sigill_hdlr): Correct insn, insn size.
	(set_fast_math) [!__x86_64__ && __sun__ && __svr4__]: Use movaps.

	gcc/testsuite:
	* lib/target-supports.exp (check_sse_os_support_available): Use
	movaps.

	libgfortran.
	* config/fpu-387.h [__sun__ && __svr4__] (sigill_hdlr): Correct
	insn, insn size.
	(has_sse) [!__x86_64__ && __sun__ && __svr4__]: Use movaps.

diff --git a/gcc/config/i386/crtfastmath.c b/gcc/config/i386/crtfastmath.c
--- a/gcc/config/i386/crtfastmath.c
+++ b/gcc/config/i386/crtfastmath.c
@@ -30,7 +30,7 @@
 #include "cpuid.h"
 #endif
 
-#if !defined __x86_64 && defined __sun__ && defined __svr4__
+#if !defined __x86_64__ && defined __sun__ && defined __svr4__
 #include <signal.h>
 #include <ucontext.h>
 
@@ -43,9 +43,9 @@ sigill_hdlr (int sig __attribute((unused
 {
   sigill_caught = 1;
   /* Set PC to the instruction after the faulting one to skip over it,
-     otherwise we enter an infinite loop.  4 is the size of the stmxcsr
+     otherwise we enter an infinite loop.  3 is the size of the movaps
      instruction.  */
-  ucp->uc_mcontext.gregs[EIP] += 4;
+  ucp->uc_mcontext.gregs[EIP] += 3;
   setcontext (ucp);
 }
 #endif
@@ -83,7 +83,7 @@ set_fast_math (void)
 
       /* We need a single SSE instruction here so the handler can safely skip
 	 over it.  */
-      __asm__ volatile ("movss %xmm2,%xmm1");
+      __asm__ volatile ("movaps %xmm0,%xmm0");
 
       sigaction (SIGILL, &oact, NULL);
 
diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp
--- a/gcc/testsuite/lib/target-supports.exp
+++ b/gcc/testsuite/lib/target-supports.exp
@@ -1059,7 +1059,7 @@ proc check_sse_os_support_available { } 
 	    check_runtime_nocache sse_os_support_available {
 		int main ()
 		{
-		    __asm__ volatile ("movss %xmm2,%xmm1");
+		    __asm__ volatile ("movaps %xmm0,%xmm0");
 		    return 0;
 		}
 	    } "-msse"
diff --git a/libgfortran/config/fpu-387.h b/libgfortran/config/fpu-387.h
--- a/libgfortran/config/fpu-387.h
+++ b/libgfortran/config/fpu-387.h
@@ -1,5 +1,5 @@
 /* FPU-related code for x86 and x86_64 processors.
-   Copyright 2005, 2007, 2009, 2010 Free Software Foundation, Inc.
+   Copyright 2005, 2007, 2009, 2010, 2011 Free Software Foundation, Inc.
    Contributed by Francois-Xavier Coudert <coudert@clipper.ens.fr>
 
 This file is part of the GNU Fortran 95 runtime library (libgfortran).
@@ -40,9 +40,9 @@ sigill_hdlr (int sig __attribute((unused
 {
   sigill_caught = 1;
   /* Set PC to the instruction after the faulting one to skip over it,
-     otherwise we enter an infinite loop.  4 is the size of the stmxcsr
+     otherwise we enter an infinite loop.  3 is the size of the movaps
      instruction.  */
-  ucp->uc_mcontext.gregs[EIP] += 4;
+  ucp->uc_mcontext.gregs[EIP] += 3;
   setcontext (ucp);
 }
 #endif
@@ -73,7 +73,7 @@ has_sse (void)
 
       /* We need a single SSE instruction here so the handler can safely skip
 	 over it.  */
-      __asm__ volatile ("movss %xmm2,%xmm1");
+      __asm__ volatile ("movaps %xmm0,%xmm0");
 
       sigaction (SIGILL, &oact, NULL);
 


-- 
-----------------------------------------------------------------------------
Rainer Orth, Center for Biotechnology, Bielefeld University


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]