From: Tom Stellard <tstellar@gmail.com>
Date: Thu, 13 Oct 2011 23:32:35 +0000 (-0700)
Subject: r300/compiler: Don't pair output writes with GPR writes in the scheduler
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=51fe9994bdec1625a27e12216d492916e64ab622;p=mesa.git

r300/compiler: Don't pair output writes with GPR writes in the scheduler
---

diff --git a/src/gallium/drivers/r300/compiler/radeon_pair_schedule.c b/src/gallium/drivers/r300/compiler/radeon_pair_schedule.c
index 1f589cdb98e..ee868ccba3a 100644
--- a/src/gallium/drivers/r300/compiler/radeon_pair_schedule.c
+++ b/src/gallium/drivers/r300/compiler/radeon_pair_schedule.c
@@ -511,6 +511,13 @@ static int merge_instructions(struct rc_pair_instruction * rgb, struct rc_pair_i
 		return 0;
 	}
 
+	/* Writing output registers in the middle of shaders is slow, so
+	 * we don't want to pair output writes with temp writes. */
+	if ((rgb->RGB.OutputWriteMask && !alpha->Alpha.OutputWriteMask)
+		|| (!rgb->RGB.OutputWriteMask && alpha->Alpha.OutputWriteMask)) {
+		return 0;
+	}
+
 	memcpy(&backup, rgb, sizeof(struct rc_pair_instruction));
 
 	if (destructive_merge_instructions(rgb, alpha))