i965: avoid memsetting all the BRW_WM_MAX_INSN arrays for every compile.

For an app that's blowing out the state cache, like sauerbraten, the
memset of the giant arrays ended up taking 11% of the CPU even when only a
"few" of the entries got used.  With this, the WM program compile drops back
down to 1% of CPU time.

Bug #24981 (bisected to BRW_WM_MAX_INSN increase).

1 files changed, 2 insertions, 0 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_wm_fp.c b/src/mesa/drivers/dri/i965/brw_wm_fp.c
index 549afd31de..1c4f62ba48 100644
--- a/src/mesa/drivers/dri/i965/brw_wm_fp.c
+++ b/src/mesa/drivers/dri/i965/brw_wm_fp.c
@@ -182,6 +182,8 @@ static void release_temp( struct brw_wm_compile *c, struct prog_dst_register tem
 static struct prog_instruction *get_fp_inst(struct brw_wm_compile *c)
 {
    assert(c->nr_fp_insns < BRW_WM_MAX_INSN);
+   memset(&c->prog_instructions[c->nr_fp_insns], 0,
+	  sizeof(*c->prog_instructions));
    return &c->prog_instructions[c->nr_fp_insns++];
 }