From 4105320e4afed077194515f0c442bb0855137a6f Mon Sep 17 00:00:00 2001 From: danglin Date: Sat, 18 Aug 2012 23:16:53 +0000 Subject: [PATCH] PR middle-end/53823 * expmed.c (expand_mult): Skip synth_mult for negative coefficients if the mode is larger than a wide int and it is too costly to multiply by a positive multiplier and negate the result. git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@190505 138bc75d-0d04-0410-961f-82ee72b054a4 --- gcc/ChangeLog | 7 +++++++ gcc/expmed.c | 2 +- 2 files changed, 8 insertions(+), 1 deletion(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 2282536..1f313e9 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,10 @@ +2012-08-18 John David Anglin + + PR middle-end/53823 + * expmed.c (expand_mult): Skip synth_mult for negative coefficients + if the mode is larger than a wide int and it is too costly to multiply + by a positive multiplier and negate the result. + 2012-08-18 Steven Bosscher * sparseset.c (sparseset_alloc): Use non-clearing allocation. Tell diff --git a/gcc/expmed.c b/gcc/expmed.c index ac944f1..6c94a90 100644 --- a/gcc/expmed.c +++ b/gcc/expmed.c @@ -3261,7 +3261,6 @@ expand_mult (enum machine_mode mode, rtx op0, rtx op1, rtx target, /* Attempt to handle multiplication of DImode values by negative coefficients, by performing the multiplication by a positive multiplier and then inverting the result. */ - /* ??? How is this not slightly redundant with the neg variant? */ if (is_neg && mode_bitsize > HOST_BITS_PER_WIDE_INT) { /* Its safe to use -coeff even for INT_MIN, as the @@ -3278,6 +3277,7 @@ expand_mult (enum machine_mode mode, rtx op0, rtx op1, rtx target, &algorithm, variant); return expand_unop (mode, neg_optab, temp, target, 0); } + goto skip_synth; } /* Exclude cost of op0 from max_cost to match the cost -- 2.7.4