freedreno/ir3: Don't access beyond available regs

emit_cat5() needs to check if the last optional reg is there before it
accesses it.

Signed-off-by: Kristian H. Kristensen <hoegsberg@chromium.org>
Reviewed-by: Rob Clark <robdclark@gmail.com>

diff --git a/src/freedreno/ir3/ir3.c b/src/freedreno/ir3/ir3.c
index f209585dd9a0bdb07010952ff8a5056146801b43..1bded7dd1229c02403e554b9704b4adad5f8c2f0 100644 (file)
--- a/src/freedreno/ir3/ir3.c
+++ b/src/freedreno/ir3/ir3.c
@@ -451,10 +451,13 @@ static int emit_cat5(struct ir3_instruction *instr, void *ptr,
         * than tex/sampler idx, we use the first src reg in the ir to hold
         * samp_tex hvec2:
         */
-       struct ir3_register *src1 = instr->regs[2];
-       struct ir3_register *src2 = instr->regs[3];
+       struct ir3_register *src1;
+       struct ir3_register *src2;
        instr_cat5_t *cat5 = ptr;
 
+       iassert((instr->regs_count == 2) ||
+                       (instr->regs_count == 3) || (instr->regs_count == 4));
+
        switch (instr->opc) {
        case OPC_DSX:
        case OPC_DSXPP_1:
@@ -462,11 +465,11 @@ static int emit_cat5(struct ir3_instruction *instr, void *ptr,
        case OPC_DSYPP_1:
                iassert((instr->flags & IR3_INSTR_S2EN) == 0);
                src1 = instr->regs[1];
-               src2 = instr->regs[2];
+               src2 = instr->regs_count > 2 ? instr->regs[2] : NULL;
                break;
        default:
                src1 = instr->regs[2];
-               src2 = instr->regs[3];
+               src2 = instr->regs_count > 3 ? instr->regs[3] : NULL;
                break;
        }