Mesa (master): r600/shader: only emit add instruction if param has a value.

[Dave Airlie]

Module: Mesa
Branch: master
Commit: 7efcafce7c6dd3dc9e71c7d35d6f7ebfd88f106b
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=7efcafce7c6dd3dc9e71c7d35d6f7ebfd88f106b

Author: Dave Airlie <airlied at redhat.com>
Date:   Wed Jan 10 02:56:15 2018 +0000

r600/shader: only emit add instruction if param has a value.

Just saves a pointless a = a + 0;

Reviewed-by: Roland Scheidegger <sroland at vmware.com>
Signed-off-by: Dave Airlie <airlied at redhat.com>

---

 src/gallium/drivers/r600/r600_shader.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/src/gallium/drivers/r600/r600_shader.c b/src/gallium/drivers/r600/r600_shader.c
index 623e6f7f70..cfc3400f92 100644
--- a/src/gallium/drivers/r600/r600_shader.c
+++ b/src/gallium/drivers/r600/r600_shader.c
@@ -2864,12 +2864,14 @@ static int r600_tess_factor_read(struct r600_shader_ctx *ctx,
 	if (r)
 		return r;
 
-	r = single_alu_op2(ctx, ALU_OP2_ADD_INT,
-			   temp_reg, 0,
-			   temp_reg, 0,
-			   V_SQ_ALU_SRC_LITERAL, param * 16);
-	if (r)
-		return r;
+	if (param) {
+		r = single_alu_op2(ctx, ALU_OP2_ADD_INT,
+				   temp_reg, 0,
+				   temp_reg, 0,
+				   V_SQ_ALU_SRC_LITERAL, param * 16);
+		if (r)
+			return r;
+	}
 
 	do_lds_fetch_values(ctx, temp_reg, dreg, ((1u << nc) - 1));
 	return 0;