From: Matt Turner <mattst88@gmail.com>
Date: Tue, 11 Nov 2014 23:56:58 +0000 (-0800)
Subject: i965: Don't treat IF or WHILE with cmod as writing the flag.
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=f1e5418f402c7ac087b1c127cb4476d0d02e0073;p=mesa.git

i965: Don't treat IF or WHILE with cmod as writing the flag.

Sandybridge's IF and WHILE instructions can do an embedded comparison
with conditional mod.

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

diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp
index 028eff23efa..37015ec607b 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs.cpp
@@ -933,7 +933,9 @@ fs_inst::reads_flag() const
 bool
 fs_inst::writes_flag() const
 {
-   return (conditional_mod && opcode != BRW_OPCODE_SEL) ||
+   return (conditional_mod && (opcode != BRW_OPCODE_SEL &&
+                               opcode != BRW_OPCODE_IF &&
+                               opcode != BRW_OPCODE_WHILE)) ||
           opcode == FS_OPCODE_MOV_DISPATCH_TO_FLAGS;
 }
 
diff --git a/src/mesa/drivers/dri/i965/brw_vec4.h b/src/mesa/drivers/dri/i965/brw_vec4.h
index 7d814ca65bd..abdab993be9 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4.h
+++ b/src/mesa/drivers/dri/i965/brw_vec4.h
@@ -234,7 +234,9 @@ public:
 
    bool writes_flag()
    {
-      return conditional_mod && opcode != BRW_OPCODE_SEL;
+      return (conditional_mod && (opcode != BRW_OPCODE_SEL &&
+                                  opcode != BRW_OPCODE_IF &&
+                                  opcode != BRW_OPCODE_WHILE));
    }
 };