From: Alejandro Piñeiro <apinheiro@igalia.com>
Date: Fri, 23 Oct 2015 13:32:30 +0000 (+0200)
Subject: i965/vec4: check opcode on vec4_instruction::reads_flag(channel)
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=2f1bc1da864f8d169427b911bf60e1023321e420;p=mesa.git

i965/vec4: check opcode on vec4_instruction::reads_flag(channel)

Commit f17b78 added an alternative reads_flag(channel) that returned
if the instruction was reading a specific channel flag. By mistake it
only took into account the predicate, but when the opcode is
VS_OPCODE_UNPACK_FLAGS_SIMD4X2 there isn't any predicate, but the flag
are used.

That mistake caused some regressions on old hw. More information on
this bug:
https://bugs.freedesktop.org/show_bug.cgi?id=92621

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
---

diff --git a/src/mesa/drivers/dri/i965/brw_ir_vec4.h b/src/mesa/drivers/dri/i965/brw_ir_vec4.h
index 74e9733bd44..cc4104c8eb3 100644
--- a/src/mesa/drivers/dri/i965/brw_ir_vec4.h
+++ b/src/mesa/drivers/dri/i965/brw_ir_vec4.h
@@ -188,8 +188,8 @@ public:
 
    bool reads_flag(unsigned c)
    {
-      if (!reads_flag())
-         return false;
+      if (opcode == VS_OPCODE_UNPACK_FLAGS_SIMD4X2)
+         return true;
 
       switch (predicate) {
       case BRW_PREDICATE_NONE: