Mesa (master): r300/compiler: Use zero as the register index for unused sources

[Tom Stellard]

Module: Mesa
Branch: master
Commit: d668659003d0164f0d9c805f4127ff8eb64f0624
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=d668659003d0164f0d9c805f4127ff8eb64f0624

Author: Tom Stellard <tstellar at gmail.com>
Date:   Thu Nov 11 01:01:13 2010 -0800

r300/compiler: Use zero as the register index for unused sources

This fixes an invalid "Too many hardware temporaries used" error in the
case where a source reads from a temporary register with an index greater
than max_temp_regs and then the source is marked as unused before the
register allocation pass.

NOTE: This is a candidate for the 7.9 branch.

---

 .../drivers/dri/r300/compiler/r300_fragprog_emit.c |    3 +++
 .../drivers/dri/r300/compiler/r500_fragprog_emit.c |    3 +++
 2 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/src/mesa/drivers/dri/r300/compiler/r300_fragprog_emit.c b/src/mesa/drivers/dri/r300/compiler/r300_fragprog_emit.c
index 8be32ea..1db8678 100644
--- a/src/mesa/drivers/dri/r300/compiler/r300_fragprog_emit.c
+++ b/src/mesa/drivers/dri/r300/compiler/r300_fragprog_emit.c
@@ -76,6 +76,9 @@ static void use_temporary(struct r300_fragment_program_code *code, unsigned int
 
 static unsigned int use_source(struct r300_fragment_program_code* code, struct rc_pair_instruction_source src)
 {
+	if (!src.Used)
+		return 0;
+
 	if (src.File == RC_FILE_CONSTANT) {
 		return src.Index | (1 << 5);
 	} else if (src.File == RC_FILE_TEMPORARY) {
diff --git a/src/mesa/drivers/dri/r300/compiler/r500_fragprog_emit.c b/src/mesa/drivers/dri/r300/compiler/r500_fragprog_emit.c
index 6f101c6..0311e7c 100644
--- a/src/mesa/drivers/dri/r300/compiler/r500_fragprog_emit.c
+++ b/src/mesa/drivers/dri/r300/compiler/r500_fragprog_emit.c
@@ -200,6 +200,9 @@ static void use_temporary(struct r500_fragment_program_code* code, unsigned int
 
 static unsigned int use_source(struct r500_fragment_program_code* code, struct rc_pair_instruction_source src)
 {
+	if (!src.Used)
+		return 0;
+
 	if (src.File == RC_FILE_CONSTANT) {
 		return src.Index | 0x100;
 	} else if (src.File == RC_FILE_TEMPORARY) {