Mesa (master): nir: Strengthen "no jumps" assertions in instruction insertion API.

[Kenneth Graunke]

Module: Mesa
Branch: master
Commit: c44d50775209266b5c8bad0ab7a7c4ccd7db14a4
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=c44d50775209266b5c8bad0ab7a7c4ccd7db14a4

Author: Kenneth Graunke <kenneth at whitecape.org>
Date:   Mon Aug 24 17:30:08 2015 -0700

nir: Strengthen "no jumps" assertions in instruction insertion API.

Jumps must be the last instruction in a block, so inserting another
instruction after a jump is illegal.

Previously, we only checked this when the new instruction being inserted
was a jump.  This is a red herring - inserting *any* kind of instruction
after a jump is illegal.

Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
Reviewed-by: Jason Ekstrand <jason.ekstrand at intel.com>
Acked-by: Connor Abbott <cwabbott0 at gmail.com>

---

 src/glsl/nir/nir.c |   10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/glsl/nir/nir.c b/src/glsl/nir/nir.c
index 77cc4f0..ff758f4 100644
--- a/src/glsl/nir/nir.c
+++ b/src/glsl/nir/nir.c
@@ -675,9 +675,10 @@ nir_instr_insert_before(nir_instr *instr, nir_instr *before)
 void
 nir_instr_insert_after(nir_instr *instr, nir_instr *after)
 {
+   assert(instr->type != nir_instr_type_jump);
+
    if (after->type == nir_instr_type_jump) {
       assert(instr == nir_block_last_instr(instr->block));
-      assert(instr->type != nir_instr_type_jump);
    }
 
    after->block = instr->block;
@@ -705,10 +706,9 @@ nir_instr_insert_before_block(nir_block *block, nir_instr *before)
 void
 nir_instr_insert_after_block(nir_block *block, nir_instr *after)
 {
-   if (after->type == nir_instr_type_jump) {
-      assert(exec_list_is_empty(&block->instr_list) ||
-             nir_block_last_instr(block)->type != nir_instr_type_jump);
-   }
+   nir_instr *last = nir_block_last_instr(block);
+   assert(last == NULL || last->type != nir_instr_type_jump);
+   (void) last;
 
    after->block = block;
    add_defs_uses(after);