Mesa (master): i965: Collect GLSL src/dst regs up in generic code.

[Eric Anholt]

Module: Mesa
Branch: master
Commit: 0f34cdf6210b748db77c5eba2993637f4af6faeb
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=0f34cdf6210b748db77c5eba2993637f4af6faeb

Author: Eric Anholt <eric at anholt.net>
Date:   Wed Aug 12 12:56:35 2009 -0700

i965: Collect GLSL src/dst regs up in generic code.

This matches brw_wm_emit.c, which we'll be using shortly.  There's a
possible penalty here in that we'll allocate registers for unused channels,
since we aren't doing ref tracking like brw_wm_pass*.c does.  However, my
measurements on GM965 don't show any for either OA or UT2004 with the GLSL
path forced.

---

 src/mesa/drivers/dri/i965/brw_wm.h      |    2 ++
 src/mesa/drivers/dri/i965/brw_wm_glsl.c |   22 +++++++++++++++-------
 2 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/brw_wm.h b/src/mesa/drivers/dri/i965/brw_wm.h
index 47aa4da..f841d25 100644
--- a/src/mesa/drivers/dri/i965/brw_wm.h
+++ b/src/mesa/drivers/dri/i965/brw_wm.h
@@ -162,6 +162,8 @@ struct brw_wm_instruction {
 #define BRW_WM_MAX_CONST 256
 #define BRW_WM_MAX_SUBROUTINE 16
 
+/* used in masks next to WRITEMASK_*. */
+#define SATURATE (1<<5)
 
 
 /* New opcodes to track internal operations required for WM unit.
diff --git a/src/mesa/drivers/dri/i965/brw_wm_glsl.c b/src/mesa/drivers/dri/i965/brw_wm_glsl.c
index 28d6d4e..fd6d6c5 100644
--- a/src/mesa/drivers/dri/i965/brw_wm_glsl.c
+++ b/src/mesa/drivers/dri/i965/brw_wm_glsl.c
@@ -2771,6 +2771,21 @@ static void brw_wm_emit_glsl(struct brw_context *brw, struct brw_wm_compile *c)
         if (c->fp->use_const_buffer)
            fetch_constants(c, inst);
 
+	if (inst->Opcode != OPCODE_ARL) {
+	   for (j = 0; j < 4; j++) {
+	      if (inst->DstReg.WriteMask & (1 << j))
+		 dst[j] = get_dst_reg(c, inst, j);
+	      else
+		 dst[j] = brw_null_reg();
+	   }
+	}
+	for (j = 0; j < brw_wm_nr_args(inst->Opcode); j++)
+	    get_argument_regs(c, inst, j, args[j], WRITEMASK_XYZW);
+
+	dst_flags = inst->DstReg.WriteMask;
+	if (inst->SaturateMode == SATURATE_ZERO_ONE)
+	    dst_flags |= SATURATE;
+
 	if (inst->CondUpdate)
 	    brw_set_conditionalmod(p, BRW_CONDITIONAL_NZ);
 	else
@@ -2866,13 +2881,6 @@ static void brw_wm_emit_glsl(struct brw_context *brw, struct brw_wm_compile *c)
 		break;
 	    case OPCODE_DDX:
 	    case OPCODE_DDY:
-		for (j = 0; j < 4; j++) {
-		    if (inst->DstReg.WriteMask & (1 << j))
-			dst[j] = get_dst_reg(c, inst, j);
-		    else
-			dst[j] = brw_null_reg();
-		}
-		get_argument_regs(c, inst, 0, args[0], WRITEMASK_XYZW);
 		emit_ddxy(p, dst, dst_flags, (inst->Opcode == OPCODE_DDX),
 			  args[0]);
                 break;