From 5be11d22368c4fd520983ab78a9ac8fc10d79929 Mon Sep 17 00:00:00 2001 From: Iago Toral Quiroga Date: Thu, 3 Dec 2015 09:50:49 +0100 Subject: [PATCH] i965: Skip execution size adjustment for instructions of width 4 This code in brw_set_dest adjusts the execution size of any instruction with a dst.width < 8. However, we don't want to do this with instructions operating on doubles, since these will have a width of 4, but still need an execution size of 8 (for SIMD8). Unfortunately, we can't just check the size of the operands involved to detect if we are doing an operation on doubles, because we can have instructions that do operations on double operands interpreted as UD, operating on any of its 2 32-bit components. Previous commits have made it so we never emit instructions with a horizontal width of 4 that don't have the correct execution size set for gen6+, so we can skip it in this case, avoiding the conflicts with fp64 requirements. Expanding the same fix to other hardware generations requires many more changes but since we are not targetting fp64 support on them wer don't really care for now. Reviewed-by: Topi Pohjolainen --- src/mesa/drivers/dri/i965/brw_eu_emit.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/src/mesa/drivers/dri/i965/brw_eu_emit.c b/src/mesa/drivers/dri/i965/brw_eu_emit.c index 1f3b32e55d8..0b99356b27d 100644 --- a/src/mesa/drivers/dri/i965/brw_eu_emit.c +++ b/src/mesa/drivers/dri/i965/brw_eu_emit.c @@ -202,8 +202,20 @@ brw_set_dest(struct brw_codegen *p, brw_inst *inst, struct brw_reg dest) /* Generators should set a default exec_size of either 8 (SIMD4x2 or SIMD8) * or 16 (SIMD16), as that's normally correct. However, when dealing with * small registers, we automatically reduce it to match the register size. + * + * In platforms that support fp64 we can emit instructions with a width of + * 4 that need two SIMD8 registers and an exec_size of 8 or 16. In these + * cases we need to make sure that these instructions have their exec sizes + * set properly when they are emitted and we can't rely on this code to fix + * it. */ - if (dest.width < BRW_EXECUTE_8) + bool fix_exec_size; + if (devinfo->gen >= 6) + fix_exec_size = dest.width < BRW_EXECUTE_4; + else + fix_exec_size = dest.width < BRW_EXECUTE_8; + + if (fix_exec_size) brw_inst_set_exec_size(devinfo, inst, dest.width); } -- 2.30.2