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| author | Richard Henderson <rth@redhat.com> | 2005-05-18 23:29:45 -0700 |
|---|---|---|
| committer | Richard Henderson <rth@gcc.gnu.org> | 2005-05-18 23:29:45 -0700 |
| commit | d2751e9ed5e31a902b308114082fe4a53e808564 (patch) | |
| tree | c21523868f20e9be133621772715cb46382fcfbd | |
| parent | e82766657d896c6d935d50bc5820245208075d62 (diff) | |
| download | gcc-d2751e9ed5e31a902b308114082fe4a53e808564.zip gcc-d2751e9ed5e31a902b308114082fe4a53e808564.tar.gz gcc-d2751e9ed5e31a902b308114082fe4a53e808564.tar.bz2 | |
re PR tree-optimization/21541 (gcc.c-torture/execute/20031215-1.c compilation fails)
PR 21541
* ifcvt.c (noce_process_if_block): Avoid conversion when the
memory destination is readonly.
From-SVN: r99951
| -rw-r--r-- | gcc/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/ifcvt.c | 8 |
2 files changed, 14 insertions, 0 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index fb7cc49..10657a4 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,6 +1,12 @@ 2005-05-18 Richard Henderson <rth@redhat.com> PR 21541 + * ifcvt.c (noce_process_if_block): Avoid conversion when the + memory destination is readonly. + +2005-05-18 Richard Henderson <rth@redhat.com> + + PR 21541 * tree-ssa-operands.c (opf_non_specific): New. (get_asm_expr_operands): Set it. (add_call_clobber_ops, add_call_read_ops): Likewise. diff --git a/gcc/ifcvt.c b/gcc/ifcvt.c index 8367316..be02aaa 100644 --- a/gcc/ifcvt.c +++ b/gcc/ifcvt.c @@ -1981,6 +1981,14 @@ noce_process_if_block (struct ce_if_block * ce_info) if (side_effects_p (x)) return FALSE; + /* If x is a read-only memory, then the program is valid only if we + avoid the store into it. If there are stores on both the THEN and + ELSE arms, then we can go ahead with the conversion; either the + program is broken, or the condition is always false such that the + other memory is selected. */ + if (!set_b && MEM_P (x) && MEM_READONLY_P (x)) + return FALSE; + b = (set_b ? SET_SRC (set_b) : x); /* Only operate on register destinations, and even then avoid extending |