Mesa (master): freedreno/a3xx/compiler: collapse nop's with repeat

[Rob Clark]

Module: Mesa
Branch: master
Commit: 9bbfae62657f44251562174ac1f80b2e4278a52d
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=9bbfae62657f44251562174ac1f80b2e4278a52d

Author: Rob Clark <robclark at freedesktop.org>
Date:   Fri Feb 21 18:03:30 2014 -0500

freedreno/a3xx/compiler: collapse nop's with repeat

Easier than making more extensive use of rpt, and the more compact
shaders seem to bring some bit of performance boost.  (Perhaps repeat
flag benefits are more than just instruction cache, possibly it saves
on instruction decode as well?)

Signed-off-by: Rob Clark <robclark at freedesktop.org>

---

 src/gallium/drivers/freedreno/a3xx/ir3.h    |    5 +++++
 src/gallium/drivers/freedreno/a3xx/ir3_ra.c |   10 ++++++++++
 2 files changed, 15 insertions(+)

diff --git a/src/gallium/drivers/freedreno/a3xx/ir3.h b/src/gallium/drivers/freedreno/a3xx/ir3.h
index 9c57a65..894db17 100644
--- a/src/gallium/drivers/freedreno/a3xx/ir3.h
+++ b/src/gallium/drivers/freedreno/a3xx/ir3.h
@@ -312,6 +312,11 @@ static inline bool is_flow(struct ir3_instruction *instr)
 	return (instr->category == 0);
 }
 
+static inline bool is_nop(struct ir3_instruction *instr)
+{
+	return is_flow(instr) && (instr->opc == OPC_NOP);
+}
+
 static inline bool is_alu(struct ir3_instruction *instr)
 {
 	return (1 <= instr->category) && (instr->category <= 3);
diff --git a/src/gallium/drivers/freedreno/a3xx/ir3_ra.c b/src/gallium/drivers/freedreno/a3xx/ir3_ra.c
index 5df57e7..06a86ff 100644
--- a/src/gallium/drivers/freedreno/a3xx/ir3_ra.c
+++ b/src/gallium/drivers/freedreno/a3xx/ir3_ra.c
@@ -542,6 +542,16 @@ static void legalize(struct ir3_ra_ctx *ctx, struct ir3_block *block)
 		if ((shader->instrs_count == 0) && (n->category >= 5))
 			ir3_instr_create(block, 0, OPC_NOP);
 
+		if (is_nop(n) && shader->instrs_count) {
+			struct ir3_instruction *last =
+					shader->instrs[shader->instrs_count-1];
+			if (is_nop(last) && (last->repeat < 5)) {
+				last->repeat++;
+				last->flags |= n->flags;
+				continue;
+			}
+		}
+
 		shader->instrs[shader->instrs_count++] = n;
 
 		if (is_sfu(n))