aboutsummaryrefslogtreecommitdiff
path: root/gcc
diff options
context:
space:
mode:
authorJeffrey A Law <law@cygnus.com>1999-08-31 06:28:16 +0000
committerJeff Law <law@gcc.gnu.org>1999-08-31 00:28:16 -0600
commit835126657b0fcfa7515b819c156751dfc10c9d5a (patch)
treeefe6a39dde5dee4ab7324404a9bb42925b184498 /gcc
parentf425a8879b121e9145d9ce6a614cad1fc41bd50e (diff)
downloadgcc-835126657b0fcfa7515b819c156751dfc10c9d5a.zip
gcc-835126657b0fcfa7515b819c156751dfc10c9d5a.tar.gz
gcc-835126657b0fcfa7515b819c156751dfc10c9d5a.tar.bz2
emit-rtl.c (copy_rtx_if_shared): A MEM which references virtual_stack_vars_rtx or virtual_incoming_args_rtx can...
* emit-rtl.c (copy_rtx_if_shared): A MEM which references virtual_stack_vars_rtx or virtual_incoming_args_rtx can not be shared. From-SVN: r29001
Diffstat (limited to 'gcc')
-rw-r--r--gcc/ChangeLog10
-rw-r--r--gcc/emit-rtl.c16
2 files changed, 15 insertions, 11 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 0279ec0..caf5c00 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -42,10 +42,6 @@ Mon Aug 30 16:07:49 1999 Richard Henderson <rth@cygnus.com>
* flow.c (new_insn_dead_notes): Use sets_reg_or_subreg not
mark_set_resources.
-Mon Aug 30 16:36:33 1999 Jeffrey A Law (law@cygnus.com)
-
- * invoke.texi: Fix typo.
-
Mon Aug 30 12:23:53 1999 Jim Wilson <wilson@cygnus.com>
* fixinc/Makefile.in (subdir): New.
@@ -54,6 +50,12 @@ Mon Aug 30 12:23:53 1999 Jim Wilson <wilson@cygnus.com>
Mon Aug 30 01:02:09 1999 Jeffrey A Law (law@cygnus.com)
+ * emit-rtl.c (copy_rtx_if_shared): A MEM which references
+ virtual_stack_vars_rtx or virtual_incoming_args_rtx can not
+ be shared.
+
+ * invoke.texi: Fix typo.
+
* dwarf2out.c (mem_loc_descriptor): New argument MODE. All callers
changed. Handle autoincrement addressing modes.
diff --git a/gcc/emit-rtl.c b/gcc/emit-rtl.c
index b028556..79c179c 100644
--- a/gcc/emit-rtl.c
+++ b/gcc/emit-rtl.c
@@ -1678,16 +1678,18 @@ copy_rtx_if_shared (orig)
return x;
case MEM:
- /* A MEM is allowed to be shared if its address is constant
- or is a constant plus one of the special registers. */
- if (CONSTANT_ADDRESS_P (XEXP (x, 0))
- || XEXP (x, 0) == virtual_stack_vars_rtx
- || XEXP (x, 0) == virtual_incoming_args_rtx)
+ /* A MEM is allowed to be shared if its address is constant.
+
+ We used to allow sharing of MEMs which referenced
+ virtual_stack_vars_rtx or virtual_incoming_args_rtx, but
+ that can lose. instantiate_virtual_regs will not unshare
+ the MEMs, and combine may change the structure of the address
+ because it looks safe and profitable in one context, but
+ in some other context it creates unrecognizable RTL. */
+ if (CONSTANT_ADDRESS_P (XEXP (x, 0)))
return x;
if (GET_CODE (XEXP (x, 0)) == PLUS
- && (XEXP (XEXP (x, 0), 0) == virtual_stack_vars_rtx
- || XEXP (XEXP (x, 0), 0) == virtual_incoming_args_rtx)
&& CONSTANT_ADDRESS_P (XEXP (XEXP (x, 0), 1)))
{
/* This MEM can appear in more than one place,