mesa: check dst reg in _mesa_find_free_register()
If a register was only being used as a destination (as will happen when
generated condition-codes) we missed its use. So we'd errantly return
a register index that was really in-use, not free.
Fixes bug 25579.
diff --git a/src/mesa/shader/program.c b/src/mesa/shader/program.c
index 2cd6eb8..18d4ef9 100644
--- a/src/mesa/shader/program.c
+++ b/src/mesa/shader/program.c
@@ -813,9 +813,17 @@
const struct prog_instruction *inst = prog->Instructions + i;
const GLuint n = _mesa_num_inst_src_regs(inst->Opcode);
- for (k = 0; k < n; k++) {
- if (inst->SrcReg[k].File == regFile) {
- used[inst->SrcReg[k].Index] = GL_TRUE;
+ /* check dst reg first */
+ if (inst->DstReg.File == regFile) {
+ used[inst->DstReg.Index] = GL_TRUE;
+ }
+ else {
+ /* check src regs otherwise */
+ for (k = 0; k < n; k++) {
+ if (inst->SrcReg[k].File == regFile) {
+ used[inst->SrcReg[k].Index] = GL_TRUE;
+ break;
+ }
}
}
}