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authorsayle <sayle@138bc75d-0d04-0410-961f-82ee72b054a4>2003-12-16 02:22:59 +0000
committersayle <sayle@138bc75d-0d04-0410-961f-82ee72b054a4>2003-12-16 02:22:59 +0000
commit5c8ef8c3944ede38b7b4bfa36c9c2697c050d999 (patch)
treeb02900d53cb5f257d74a47dcc26cadd3b2198c39 /gcc/ifcvt.c
parentd3d36188118a268c29a07839aced0771853130a7 (diff)
downloadppe42-gcc-5c8ef8c3944ede38b7b4bfa36c9c2697c050d999.tar.gz
ppe42-gcc-5c8ef8c3944ede38b7b4bfa36c9c2697c050d999.zip
PR middle-end/13400
* ifcvt.c (noce_process_if_block): Disable unconditional write optimizations if we could introduce a store to trapping memory that wasn't present previously. * gcc.c-torture/execute/20031215-1.c: New test case. git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@74663 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/ifcvt.c')
-rw-r--r--gcc/ifcvt.c19
1 files changed, 19 insertions, 0 deletions
diff --git a/gcc/ifcvt.c b/gcc/ifcvt.c
index 4a13ba2a45b..8aba0d50efc 100644
--- a/gcc/ifcvt.c
+++ b/gcc/ifcvt.c
@@ -1965,6 +1965,25 @@ noce_process_if_block (struct ce_if_block * ce_info)
goto success;
}
+ /* Disallow the "if (...) x = a;" form (with an implicit "else x = x;")
+ for most optimizations if writing to x may trap, i.e. its a memory
+ other than a static var or a stack slot. */
+ if (! set_b
+ && GET_CODE (orig_x) == MEM
+ && ! MEM_NOTRAP_P (orig_x)
+ && rtx_addr_can_trap_p (XEXP (orig_x, 0)))
+ {
+ if (HAVE_conditional_move)
+ {
+ if (noce_try_cmove (&if_info))
+ goto success;
+ if (! HAVE_conditional_execution
+ && noce_try_cmove_arith (&if_info))
+ goto success;
+ }
+ return FALSE;
+ }
+
if (noce_try_move (&if_info))
goto success;
if (noce_try_store_flag (&if_info))
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