This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
[PATCH] Fix up aliasing violations in src/ia64/ffi.c (PR rtl-optimization/48496)
- From: Jakub Jelinek <jakub at redhat dot com>
- To: Steve Ellcey <sje at cup dot hp dot com>, libffi-discuss at sourceware dot org
- Cc: gcc-patches at gcc dot gnu dot org, Richard Guenther <rguenther at suse dot de>
- Date: Thu, 19 Jan 2012 10:20:28 +0100
- Subject: [PATCH] Fix up aliasing violations in src/ia64/ffi.c (PR rtl-optimization/48496)
- Reply-to: Jakub Jelinek <jakub at redhat dot com>
Hi!
For FFI_TYPE_FLOAT and FFI_TYPE_DOUBLE, I think src/ia64/ffi.c violates
aliasing by accessing the same object through incompatible lvalues
(in an asm operand through float resp. double lvalue and on the next
line through UINT32 resp. UINT64 lvalue.
GCC apparently errors out on this while reloading the asm, but only
without -fno-strict-aliasing, which it shouldn't, nevertheless IMHO
libffi shouldn't violate aliasing in the first place, which I'd say
would demote that PR from P1 to P2.
For FFI_TYPE_LONGDOUBLE we already do the right thing.
Ok for trunk?
2012-01-19 Jakub Jelinek <jakub@redhat.com>
PR rtl-optimization/48496
* src/ia64/ffi.c (ffi_call): Fix up aliasing violations.
--- libffi/src/ia64/ffi.c 2010-08-11 21:08:14.000000000 +0200
+++ libffi/src/ia64/ffi.c 2012-01-14 18:43:35.652923850 +0100
@@ -324,13 +324,17 @@ ffi_call(ffi_cif *cif, void (*fn)(void),
case FFI_TYPE_FLOAT:
if (gpcount < 8 && fpcount < 8)
stf_spill (&stack->fp_regs[fpcount++], *(float *)avalue[i]);
- stack->gp_regs[gpcount++] = *(UINT32 *)avalue[i];
+ {
+ UINT32 tmp;
+ memcpy (&tmp, avalue[i], sizeof (UINT32));
+ stack->gp_regs[gpcount++] = tmp;
+ }
break;
case FFI_TYPE_DOUBLE:
if (gpcount < 8 && fpcount < 8)
stf_spill (&stack->fp_regs[fpcount++], *(double *)avalue[i]);
- stack->gp_regs[gpcount++] = *(UINT64 *)avalue[i];
+ memcpy (&stack->gp_regs[gpcount++], avalue[i], sizeof (UINT64));
break;
case FFI_TYPE_LONGDOUBLE:
Jakub