<div dir="ltr"><div class="gmail_extra"><div class="gmail_quote">On Wed, Feb 8, 2017 at 2:20 PM, Elie Tournier <span dir="ltr"><<a href="mailto:tournier.elie@gmail.com" target="_blank">tournier.elie@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><span class="">Signed-off-by: Elie Tournier <<a href="mailto:tournier.elie@gmail.com">tournier.elie@gmail.com</a>><br>
---<br>
</span> src/compiler/nir/nir_opt_loop_<wbr>unroll.c | 10 +++++++++-<br>
1 file changed, 9 insertions(+), 1 deletion(-)<br>
<br>
diff --git a/src/compiler/nir/nir_opt_<wbr>loop_unroll.c b/src/compiler/nir/nir_opt_<wbr>loop_unroll.c<br>
index 37cbced43d..035a030239 100644<br>
--- a/src/compiler/nir/nir_opt_<wbr>loop_unroll.c<br>
+++ b/src/compiler/nir/nir_opt_<wbr>loop_unroll.c<br>
@@ -26,6 +26,14 @@<br>
<span class=""> #include "nir_control_flow.h"<br>
#include "nir_loop_analyze.h"<br>
<br>
+<br>
</span>+/* This limit is chosen fairly arbitrarily. The GLSL IR limit is 25.<br>
+ * However, due to slight differences in the way the two IRs count<br>
+ * instructions, some loops that would unroll with GLSL IR fail to unroll<br>
+ * if we set this to 25 so we set it to 26.<br></blockquote><div><br></div><div>Ok, I lied in my comment. It's not 25, it's 32. Tim, can you explain the discrepancy?<br></div><div>--Jason<br></div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
+ */<br>
+#define LOOP_UNROLL_LIMIT 26<br>
<span class="">+<br>
/* Prepare this loop for unrolling by first converting to lcssa and then<br>
* converting the phis from the loops first block and the block that follows<br>
* the loop into regs. Partially converting out of SSA allows us to unroll<br>
</span>@@ -460,7 +468,7 @@ is_loop_small_enough_to_<wbr>unroll(nir_shader *shader, nir_loop_info *li)<br>
<span class=""> return true;<br>
<br>
bool loop_not_too_large =<br>
- li->num_instructions * li->trip_count <= max_iter * 26;<br>
</span>+ li->num_instructions * li->trip_count <= max_iter * LOOP_UNROLL_LIMIT;<br>
<br>
return loop_not_too_large;<br>
}<br>
<span class="HOEnZb"><font color="#888888">--<br>
2.11.0<br>
<br>
</font></span></blockquote></div><br></div></div>