Mesa (master): nvc0: kick out empty live ranges

[Christoph Bumiller]

Module: Mesa
Branch: master
Commit: f01748355360ac98c772ce8b82ca0e6c2f94629a
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=f01748355360ac98c772ce8b82ca0e6c2f94629a

Author: Christoph Bumiller <e0425955 at student.tuwien.ac.at>
Date:   Tue Feb 22 21:50:17 2011 +0100

nvc0: kick out empty live ranges

They affect overlap tests even though they're actually empty.

---

 src/gallium/drivers/nvc0/nvc0_pc_regalloc.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/src/gallium/drivers/nvc0/nvc0_pc_regalloc.c b/src/gallium/drivers/nvc0/nvc0_pc_regalloc.c
index d721394..f4afe08 100644
--- a/src/gallium/drivers/nvc0/nvc0_pc_regalloc.c
+++ b/src/gallium/drivers/nvc0/nvc0_pc_regalloc.c
@@ -87,6 +87,9 @@ add_range_ex(struct nv_value *val, int bgn, int end, struct nv_range *new_range)
 {
    struct nv_range *range, **nextp = &val->livei;
 
+   if (bgn == end) /* [a, a) is invalid / empty */
+      return TRUE;
+
    for (range = val->livei; range; range = range->next) {
       if (end < range->bgn)
          break; /* insert before */