<div dir="ltr">I have no real opinion on this patch. Matt? Ken?<br></div><div class="gmail_extra"><br><div class="gmail_quote">On Wed, Dec 21, 2016 at 6:26 PM, Timothy Arceri <span dir="ltr"><<a href="mailto:timothy.arceri@collabora.com" target="_blank">timothy.arceri@collabora.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">There is a single regression in loop unrolling which is:<br>
<br>
loops HURT: shaders/orbital_explorer.<wbr>shader_test GS SIMD8: 0 -> 1<br>
<br>
However the loop is huge so it seems reasonable not to unroll it. It's<br>
surprising that GLSL IR does unroll it.<br>
<br>
shader-db results BDW:<br>
<br>
total instructions in shared programs: 13037455 -> 13036947 (-0.00%)<br>
instructions in affected programs: 17982 -> 17474 (-2.83%)<br>
helped: 63<br>
HURT: 25<br>
<br>
total cycles in shared programs: 262217870 -> 262227990 (0.00%)<br>
cycles in affected programs: 2287046 -> 2297166 (0.44%)<br>
helped: 969<br>
HURT: 844<br>
<br>
total loops in shared programs: 2951 -> 2952 (0.03%)<br>
loops in affected programs: 0 -> 1<br>
helped: 0<br>
HURT: 1<br>
<br>
LOST: 0<br>
GAINED: 1<br>
---<br>
src/mesa/drivers/dri/i965/brw_<wbr>compiler.c | 2 +-<br>
1 file changed, 1 insertion(+), 1 deletion(-)<br>
<br>
diff --git a/src/mesa/drivers/dri/i965/<wbr>brw_compiler.c b/src/mesa/drivers/dri/i965/<wbr>brw_compiler.c<br>
index d7900a7..fa8a772 100644<br>
--- a/src/mesa/drivers/dri/i965/<wbr>brw_compiler.c<br>
+++ b/src/mesa/drivers/dri/i965/<wbr>brw_compiler.c<br>
@@ -122,7 +122,7 @@ brw_compiler_create(void *mem_ctx, const struct gen_device_info *devinfo)<br>
<br>
/* We want the GLSL compiler to emit code that uses condition codes */<br>
for (int i = 0; i < MESA_SHADER_STAGES; i++) {<br>
- compiler->glsl_compiler_<wbr>options[i].MaxUnrollIterations = 32;<br>
+ compiler->glsl_compiler_<wbr>options[i].MaxUnrollIterations = 0;<br>
compiler->glsl_compiler_<wbr>options[i].MaxIfDepth =<br>
devinfo->gen < 6 ? 16 : UINT_MAX;<br>
<span class="HOEnZb"><font color="#888888"><br>
--<br>
2.9.3<br>
<br>
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</font></span></blockquote></div><br></div>