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r300/compiler: Fix error in OMOD optimization

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Classic compiler mistake.  In the example below, the OMOD optimization
was combining instructions 4 and 10, but since there was an instruction
(#8) in between them that wrote to the same registers as instruction 10,
instruction 11 was reading the wrong value.

Example of the mistake:

Before OMOD:
4: MAD temp[0].y, temp[3]._y__, const[0]._x__, const[0]._y__;
...
8: ADD temp[2].x, temp[1].x___, -temp[4].x___;
...
10: MUL temp[2].x, const[1].y___, temp[0].y___;
11: FRC temp[5].x, temp[2].x___;

After OMOD:
4: MAD temp[2].x / 8, temp[3]._y__, const[0]._x__, const[0]._y__;
...
8: ADD temp[2].x, temp[1].x___, -temp[4].x___;
...
11: FRC temp[5].x, temp[2].x___;

https://bugs.freedesktop.org/show_bug.cgi?id=41367
This commit is contained in:
Tom Stellard 2011-10-01 15:22:24 -07:00
parent 13814b0103
commit d64c6d2ffc
1 changed files with 16 additions and 0 deletions
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16
src/gallium/drivers/r300/compiler/radeon_optimize.c
View file

@ -681,6 +681,20 @@ static void omod_filter_reader_cb(
}
}
static void omod_filter_writer_cb(
void * userdata,
struct rc_instruction * inst,
rc_register_file file,
unsigned int index,
unsigned int mask)
{
struct peephole_mul_cb_data * d = userdata;
if (file == d->Writer->File && index == d->Writer->Index &&
(mask & d->Writer->WriteMask)) {
d->Clobbered = 1;
}
}
static int peephole_mul_omod(
struct radeon_compiler * c,
struct rc_instruction * inst_mul,
@ -788,6 +802,8 @@ static int peephole_mul_omod(
inst = inst->Prev) {
rc_for_all_reads_mask(inst, omod_filter_reader_cb,
&cb_data);
rc_for_all_writes_mask(inst, omod_filter_writer_cb,
&cb_data);
if (cb_data.Clobbered) {
break;
}