i965/fs: Set MUL source type to W/UW in 64-bit mul macro on Gen8.

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
This commit is contained in:
Matt Turner 2014-09-27 17:34:51 -07:00
parent 94b68109fb
commit 05586f9bc1

View file

@ -654,8 +654,29 @@ fs_visitor::visit(ir_expression *ir)
struct brw_reg acc = retype(brw_acc_reg(dispatch_width),
this->result.type);
emit(MUL(acc, op[0], op[1]));
fs_inst *mul = emit(MUL(acc, op[0], op[1]));
emit(MACH(this->result, op[0], op[1]));
/* Until Gen8, integer multiplies read 32-bits from one source, and
* 16-bits from the other, and relying on the MACH instruction to
* generate the high bits of the result.
*
* On Gen8, the multiply instruction does a full 32x32-bit multiply,
* but in order to do a 64x64-bit multiply we have to simulate the
* previous behavior and then use a MACH instruction.
*
* FINISHME: Don't use source modifiers on src1.
*/
if (brw->gen >= 8) {
assert(mul->src[1].type == BRW_REGISTER_TYPE_D ||
mul->src[1].type == BRW_REGISTER_TYPE_UD);
if (mul->src[1].type == BRW_REGISTER_TYPE_D) {
mul->src[1].type = BRW_REGISTER_TYPE_W;
} else {
mul->src[1].type = BRW_REGISTER_TYPE_UW;
}
}
break;
}
case ir_binop_div: