freebsd-ports/lang/gcc28/files/patch-11
David E. O'Brien b756e894fa * expmed.c (expand_mult): Use 0 as add_target if should preserve
subexpressions.
* expmed.c (expand_divmod): Save last divison constant and
        if rem is same as div, don't adjust rem cost.

Submitted by:	Peter Jeremy <peter.jeremy@auss2.alcatel.com.au>
1998-08-14 09:20:23 +00:00

38 lines
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--- expmed.c.dist Sat Nov 8 14:11:58 1997
+++ expmed.c Thu Aug 13 11:18:13 1998
@@ -2249,7 +2249,8 @@
rtx shift_subtarget = preserve ? 0 : accum;
rtx add_target
= (opno == alg.ops - 1 && target != 0 && variant != add_variant
- ? target : 0);
+ && ! preserve)
+ ? target : 0;
rtx accum_target = preserve ? 0 : accum;
switch (alg.op[opno])
@@ -2716,6 +2717,7 @@
optab optab1, optab2;
int op1_is_constant, op1_is_pow2;
int max_cost, extra_cost;
+ static HOST_WIDE_INT last_div_const = 0;
op1_is_constant = GET_CODE (op1) == CONST_INT;
op1_is_pow2 = (op1_is_constant
@@ -2825,8 +2827,15 @@
size = GET_MODE_BITSIZE (mode);
#endif
+ /* Only deduct something for a REM if the last divide done was
+ for a different constant. Then set the constant of the last
+ divide. */
max_cost = div_cost[(int) compute_mode]
- - (rem_flag ? mul_cost[(int) compute_mode] + add_cost : 0);
+ - (rem_flag && ! (last_div_const != 0 && op1_is_constant
+ && INTVAL (op1) == last_div_const)
+ ? mul_cost[(int) compute_mode] + add_cost : 0);
+
+ last_div_const = ! rem_flag && op1_is_constant ? INTVAL (op1) : 0;
/* Now convert to the best mode to use. */
if (compute_mode != mode)