diff options
| author | Miod Vallat <miod@cvs.openbsd.org> | 2010-02-21 20:10:32 +0000 |
|---|---|---|
| committer | Miod Vallat <miod@cvs.openbsd.org> | 2010-02-21 20:10:32 +0000 |
| commit | 52489ddf33e07d5ee2c3e0be645848425c535550 (patch) | |
| tree | 1bc98f1aa680074d5d9d8743ad40dcd2f4e4b3ea /gnu | |
| parent | 27804e0518d7c4593b1e1d6adfcab4922dd616f4 (diff) | |
Backport a small fragment of a gcc 3.4 fix preventing too much recursion in
simplify_shift_const(), and only do this on mips64 platforms, because we are
too late in the release cycle.
This change has the nice side effect of preventing a wrong overoptimistic
optimization on mips64, when masking bit 31 of a long; which in turns causes
python to misbehave.
Help and ok otto@
Diffstat (limited to 'gnu')
| -rw-r--r-- | gnu/usr.bin/gcc/gcc/combine.c | 21 | ||||
| -rw-r--r-- | gnu/usr.bin/gcc/gcc/config/mips/openbsd.h | 3 |
2 files changed, 14 insertions, 10 deletions
diff --git a/gnu/usr.bin/gcc/gcc/combine.c b/gnu/usr.bin/gcc/gcc/combine.c index 3d113915f65..29142b7d2fc 100644 --- a/gnu/usr.bin/gcc/gcc/combine.c +++ b/gnu/usr.bin/gcc/gcc/combine.c @@ -9737,17 +9737,20 @@ simplify_shift_const (x, code, result_mode, varop, orig_count) /* If we can't do that, try to simplify the shift in each arm of the logical expression, make a new logical expression, and apply the inverse distributive law. */ - { - rtx lhs = simplify_shift_const (NULL_RTX, code, shift_mode, - XEXP (varop, 0), count); - rtx rhs = simplify_shift_const (NULL_RTX, code, shift_mode, - XEXP (varop, 1), count); +#ifdef BROKEN_SIMPLIFY_SHIFT_CONST_P + if (GET_CODE (XEXP (varop, 1)) == CONST_INT) +#endif + { + rtx lhs = simplify_shift_const (NULL_RTX, code, shift_mode, + XEXP (varop, 0), count); + rtx rhs = simplify_shift_const (NULL_RTX, code, shift_mode, + XEXP (varop, 1), count); - varop = gen_binary (GET_CODE (varop), shift_mode, lhs, rhs); - varop = apply_distributive_law (varop); + varop = gen_binary (GET_CODE (varop), shift_mode, lhs, rhs); + varop = apply_distributive_law (varop); - count = 0; - } + count = 0; + } break; case EQ: diff --git a/gnu/usr.bin/gcc/gcc/config/mips/openbsd.h b/gnu/usr.bin/gcc/gcc/config/mips/openbsd.h index 36fa6c6402b..cdb3c003f76 100644 --- a/gnu/usr.bin/gcc/gcc/config/mips/openbsd.h +++ b/gnu/usr.bin/gcc/gcc/config/mips/openbsd.h @@ -136,4 +136,5 @@ Boston, MA 02111-1307, USA. */ #undef MIPS_DEFAULT_GVALUE #define MIPS_DEFAULT_GVALUE 0 - +/* Prevent too much recursion in simplify_shift_const(). */ +#define BROKEN_SIMPLIFY_SHIFT_CONST_P |