freedreno/ir3: fix crash with samgq workaround

Need to list_delinit() before we clone the instruction to split it into
individual samgpN instructions, otherwise we get list corruption.

Tested-by: Eduardo Lima Mitev <elima@igalia.com>
Signed-off-by: Rob Clark <robdclark@chromium.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/3989>

diff --git a/src/freedreno/ir3/ir3_legalize.c b/src/freedreno/ir3/ir3_legalize.c
index 9c349bf..d5cdd6d 100644 (file)
--- a/src/freedreno/ir3/ir3_legalize.c
+++ b/src/freedreno/ir3/ir3_legalize.c
@@ -215,13 +215,14 @@ legalize_block(struct ir3_legalize_ctx *ctx, struct ir3_block *block)
                        ctx->type == MESA_SHADER_VERTEX && n->opc == OPC_SAMGQ) {
                        struct ir3_instruction *samgp;
 
+                       list_delinit(&n->node);
+
                        for (i = 0; i < 4; i++) {
                                samgp = ir3_instr_clone(n);
                                samgp->opc = OPC_SAMGP0 + i;
                                if (i > 1)
                                        samgp->flags |= IR3_INSTR_SY;
                        }
-                       list_delinit(&n->node);
                } else {
                        list_addtail(&n->node, &block->instr_list);
                }