From 6b10c37b9c3a73add73f444fe1aee73c9ec82c94 Mon Sep 17 00:00:00 2001 From: Kenneth Graunke Date: Sat, 22 Apr 2017 15:02:08 -0700 Subject: [PATCH] i965/vec4: Use reads_accumulator_implicitly(), not MACH checks. Curro pointed out that I should not just check for MACH, but use the reads_accumulator_implicitly() helper, which would also prevent the same bug with MAC and SADA2 (if we ever decide to use them). Cc: mesa-stable@lists.freedesktop.org Reviewed-by: Francisco Jerez --- src/intel/compiler/brw_vec4.cpp | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/src/intel/compiler/brw_vec4.cpp b/src/intel/compiler/brw_vec4.cpp index 4bb774bf10e..0909ddb5861 100644 --- a/src/intel/compiler/brw_vec4.cpp +++ b/src/intel/compiler/brw_vec4.cpp @@ -1071,11 +1071,11 @@ vec4_instruction::can_reswizzle(const struct gen_device_info *devinfo, if (devinfo->gen == 6 && is_math() && swizzle != BRW_SWIZZLE_XYZW) return false; - /* Don't touch MACH - it uses the accumulator results from an earlier - * MUL - so we'd need to reswizzle both. We don't do that, so just - * avoid it entirely. + /* We can't swizzle implicit accumulator access. We'd have to + * reswizzle the producer of the accumulator value in addition + * to the consumer (i.e. both MUL and MACH). Just skip this. */ - if (opcode == BRW_OPCODE_MACH) + if (reads_accumulator_implicitly()) return false; if (!can_do_writemask(devinfo) && dst_writemask != WRITEMASK_XYZW) -- 2.30.2