Mesa (master): i965: Add reads_accumulator_implicitly() function.

[Matt Turner]

Module: Mesa
Branch: master
Commit: 6541f1b4d02b52e19c95dcfb07ef5e0e81a57955
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=6541f1b4d02b52e19c95dcfb07ef5e0e81a57955

Author: Matt Turner <mattst88 at gmail.com>
Date:   Wed Apr  9 12:01:49 2014 -0700

i965: Add reads_accumulator_implicitly() function.

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

---

 src/mesa/drivers/dri/i965/brw_shader.cpp |   13 +++++++++++++
 src/mesa/drivers/dri/i965/brw_shader.h   |    1 +
 2 files changed, 14 insertions(+)

diff --git a/src/mesa/drivers/dri/i965/brw_shader.cpp b/src/mesa/drivers/dri/i965/brw_shader.cpp
index c32e66c..6e74803 100644
--- a/src/mesa/drivers/dri/i965/brw_shader.cpp
+++ b/src/mesa/drivers/dri/i965/brw_shader.cpp
@@ -663,6 +663,19 @@ backend_instruction::can_do_saturate() const
 }
 
 bool
+backend_instruction::reads_accumulator_implicitly() const
+{
+   switch (opcode) {
+   case BRW_OPCODE_MAC:
+   case BRW_OPCODE_MACH:
+   case BRW_OPCODE_SADA2:
+      return true;
+   default:
+      return false;
+   }
+}
+
+bool
 backend_instruction::has_side_effects() const
 {
    switch (opcode) {
diff --git a/src/mesa/drivers/dri/i965/brw_shader.h b/src/mesa/drivers/dri/i965/brw_shader.h
index 6bd7dc8..9ef08e5 100644
--- a/src/mesa/drivers/dri/i965/brw_shader.h
+++ b/src/mesa/drivers/dri/i965/brw_shader.h
@@ -47,6 +47,7 @@ public:
    bool is_control_flow() const;
    bool can_do_source_mods() const;
    bool can_do_saturate() const;
+   bool reads_accumulator_implicitly() const;
 
    /**
     * True if the instruction has side effects other than writing to