r300/compiler: Clear empty registers after constant folding

diff --git a/src/mesa/drivers/dri/r300/compiler/radeon_optimize.c b/src/mesa/drivers/dri/r300/compiler/radeon_optimize.c
index 41769e3..e895841 100644 (file)
--- a/src/mesa/drivers/dri/r300/compiler/radeon_optimize.c
+++ b/src/mesa/drivers/dri/r300/compiler/radeon_optimize.c
@@ -408,6 +408,7 @@ static void constant_folding_add(struct rc_instruction * inst)
 static void constant_folding(struct radeon_compiler * c, struct rc_instruction * inst)
 {
        const struct rc_opcode_info * opcode = rc_get_opcode_info(inst->U.I.Opcode);
+       unsigned int i;
 
        /* Replace 0.0, 1.0 and 0.5 immediates by their explicit swizzles */
        for(unsigned int src = 0; src < opcode->NumSrcRegs; ++src) {
@@ -480,6 +481,13 @@ static void constant_folding(struct radeon_compiler * c, struct rc_instruction *
                constant_folding_mul(inst);
        else if (inst->U.I.Opcode == RC_OPCODE_ADD)
                constant_folding_add(inst);
+
+       /* In case this instruction has been converted, make sure all of the
+        * registers that are no longer used are empty. */
+       opcode = rc_get_opcode_info(inst->U.I.Opcode);
+       for(i = opcode->NumSrcRegs; i < 3; i++) {
+               memset(&inst->U.I.SrcReg[i], 0, sizeof(struct rc_src_register));
+       }
 }
 
 /**