From: Eric Anholt <eric@anholt.net>
Date: Mon, 13 Aug 2012 06:30:18 +0000 (-0700)
Subject: i965: Fix accumulator_contains() test to also reject swizzles of the dst.
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=6754ec831e5aaec516db929c8db6e7478a2f5540;p=mesa.git

i965: Fix accumulator_contains() test to also reject swizzles of the dst.

When faced with this sequence:

	MOV	R1, c[1];
	MAD	R0, R2, R1.x, R1.y;

we were concluding that the MOV of R1 set up our accumulator and so we could
just use the previous result.  Only, it's got R1.xyzw in it instead of the
r1.y we're looking for.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=46784
NOTE: This is a candidate for the 8.0 branch.
---

diff --git a/src/mesa/drivers/dri/i965/brw_vs_emit.c b/src/mesa/drivers/dri/i965/brw_vs_emit.c
index 6169f737417..177b2b31a29 100644
--- a/src/mesa/drivers/dri/i965/brw_vs_emit.c
+++ b/src/mesa/drivers/dri/i965/brw_vs_emit.c
@@ -1743,7 +1743,7 @@ accumulator_contains(struct brw_vs_compile *c, struct brw_reg val)
    if (val.address_mode != BRW_ADDRESS_DIRECT)
       return false;
 
-   if (val.negate || val.abs)
+   if (val.negate || val.abs || val.dw1.bits.swizzle != BRW_SWIZZLE_XYZW)
       return false;
 
    switch (prev_insn->header.opcode) {