Mesa (master): i965: Use the new embedded compare in SEL on gen6 for VS MIN and MAX opcodes.

[Eric Anholt]

Module: Mesa
Branch: master
Commit: df24450bac404e2acd9569340dacc6e537fb919c
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=df24450bac404e2acd9569340dacc6e537fb919c

Author: Eric Anholt <eric at anholt.net>
Date:   Mon Nov 15 16:01:04 2010 +0800

i965: Use the new embedded compare in SEL on gen6 for VS MIN and MAX opcodes.

Cuts the extra CMP instruction that used to precede SEL.

---

 src/mesa/drivers/dri/i965/brw_vs_emit.c |   30 ++++++++++++++++++++++++------
 1 files changed, 24 insertions(+), 6 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/brw_vs_emit.c b/src/mesa/drivers/dri/i965/brw_vs_emit.c
index 7e43324..a13c3ca 100644
--- a/src/mesa/drivers/dri/i965/brw_vs_emit.c
+++ b/src/mesa/drivers/dri/i965/brw_vs_emit.c
@@ -574,9 +574,18 @@ static void emit_max( struct brw_compile *p,
 		      struct brw_reg arg0,
 		      struct brw_reg arg1 )
 {
-   brw_CMP(p, brw_null_reg(), BRW_CONDITIONAL_GE, arg0, arg1);
-   brw_SEL(p, dst, arg0, arg1);
-   brw_set_predicate_control(p, BRW_PREDICATE_NONE);
+   struct intel_context *intel = &p->brw->intel;
+
+   if (intel->gen >= 6) {
+      brw_set_conditionalmod(p, BRW_CONDITIONAL_GE);
+      brw_SEL(p, dst, arg0, arg1);
+      brw_set_conditionalmod(p, BRW_CONDITIONAL_NONE);
+      brw_set_predicate_control(p, BRW_PREDICATE_NONE);
+   } else {
+      brw_CMP(p, brw_null_reg(), BRW_CONDITIONAL_GE, arg0, arg1);
+      brw_SEL(p, dst, arg0, arg1);
+      brw_set_predicate_control(p, BRW_PREDICATE_NONE);
+   }
 }
 
 static void emit_min( struct brw_compile *p, 
@@ -584,9 +593,18 @@ static void emit_min( struct brw_compile *p,
 		      struct brw_reg arg0,
 		      struct brw_reg arg1 )
 {
-   brw_CMP(p, brw_null_reg(), BRW_CONDITIONAL_L, arg0, arg1);
-   brw_SEL(p, dst, arg0, arg1);
-   brw_set_predicate_control(p, BRW_PREDICATE_NONE);
+   struct intel_context *intel = &p->brw->intel;
+
+   if (intel->gen >= 6) {
+      brw_set_conditionalmod(p, BRW_CONDITIONAL_L);
+      brw_SEL(p, dst, arg0, arg1);
+      brw_set_conditionalmod(p, BRW_CONDITIONAL_NONE);
+      brw_set_predicate_control(p, BRW_PREDICATE_NONE);
+   } else {
+      brw_CMP(p, brw_null_reg(), BRW_CONDITIONAL_L, arg0, arg1);
+      brw_SEL(p, dst, arg0, arg1);
+      brw_set_predicate_control(p, BRW_PREDICATE_NONE);
+   }
 }
 
 static void emit_math1_gen4(struct brw_vs_compile *c,