i965: Assert that an instruction is not inserted around itself.

Reviewed-by: Francisco Jerez <currojerez@riseup.net>

diff --git a/src/mesa/drivers/dri/i965/brw_shader.cpp b/src/mesa/drivers/dri/i965/brw_shader.cpp
index 21977a231304ef9efa29c644fdb5b3c902b858eb..736deb443ddf36f26ed9dcced559b9da3f9b1457 100644 (file)
--- a/src/mesa/drivers/dri/i965/brw_shader.cpp
+++ b/src/mesa/drivers/dri/i965/brw_shader.cpp
@@ -948,6 +948,8 @@ adjust_later_block_ips(bblock_t *start_block, int ip_adjustment)
 void
 backend_instruction::insert_after(bblock_t *block, backend_instruction *inst)
 {
+   assert(this != inst);
+
    if (!this->is_head_sentinel())
       assert(inst_is_in_block(block, this) || !"Instruction not in block");
 
@@ -961,6 +963,8 @@ backend_instruction::insert_after(bblock_t *block, backend_instruction *inst)
 void
 backend_instruction::insert_before(bblock_t *block, backend_instruction *inst)
 {
+   assert(this != inst);
+
    if (!this->is_tail_sentinel())
       assert(inst_is_in_block(block, this) || !"Instruction not in block");