i965/fs: Fix constant combining for instructions that cannot accept source mods.

This is the case for SNB math instructions so we need to be careful
and insert the literal value of the immediate into the table (rather
than its absolute value) if the instruction is unable to invert the
sign of the constant on the fly.

Cc: "12.0" <mesa-stable@lists.freedesktop.org>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
This commit is contained in:
Francisco Jerez 2016-05-27 23:29:10 -07:00
parent 303ec22ed6
commit 06d8765bc0

View file

@ -147,8 +147,6 @@ struct table {
static struct imm *
find_imm(struct table *table, float val)
{
assert(signbit(val) == 0);
for (int i = 0; i < table->len; i++) {
if (table->imm[i].val == val) {
return &table->imm[i];
@ -220,7 +218,8 @@ fs_visitor::opt_combine_constants()
inst->src[i].type != BRW_REGISTER_TYPE_F)
continue;
float val = fabsf(inst->src[i].f);
float val = !inst->can_do_source_mods(devinfo) ? inst->src[i].f :
fabs(inst->src[i].f);
struct imm *imm = find_imm(&table, val);
if (imm) {
@ -301,7 +300,7 @@ fs_visitor::opt_combine_constants()
reg->stride = 0;
reg->negate = signbit(reg->f) != signbit(table.imm[i].val);
assert((isnan(reg->f) && isnan(table.imm[i].val)) ||
fabsf(reg->f) == table.imm[i].val);
fabsf(reg->f) == fabs(table.imm[i].val));
}
}