Mesa (master): spirv: Restructure the case loop in OpSwitch handling

[Jason Ekstrand]

Module: Mesa
Branch: master
Commit: 58cabae8cc8e848cfe39c7a63973c12c92a4ee96
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=58cabae8cc8e848cfe39c7a63973c12c92a4ee96

Author: Jason Ekstrand <jason.ekstrand at intel.com>
Date:   Wed Dec  6 10:09:28 2017 -0800

spirv: Restructure the case loop in OpSwitch handling

Instead of calling vtn_add_case for the default case and then looping,
add an is_default variable and do everything inside the loop.  This will
make the next commit easier.

Reviewed-by: Samuel Iglesias Gonsálvez <siglesias at igalia.com>
Reviewed-by: Ian Romanick <ian.d.romanick at intel.com>

---

 src/compiler/spirv/vtn_cfg.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/src/compiler/spirv/vtn_cfg.c b/src/compiler/spirv/vtn_cfg.c
index 25140ffc7d..28b811fc9a 100644
--- a/src/compiler/spirv/vtn_cfg.c
+++ b/src/compiler/spirv/vtn_cfg.c
@@ -425,9 +425,17 @@ vtn_cfg_walk_blocks(struct vtn_builder *b, struct list_head *cf_list,
          const uint32_t *branch_end =
             block->branch + (block->branch[0] >> SpvWordCountShift);
 
-         vtn_add_case(b, swtch, break_block, block->branch[2], 0, true);
-         for (const uint32_t *w = block->branch + 3; w < branch_end; w += 2)
-            vtn_add_case(b, swtch, break_block, w[1], w[0], false);
+         bool is_default = true;
+         for (const uint32_t *w = block->branch + 2; w < branch_end;) {
+            uint32_t literal = 0;
+            if (!is_default)
+               literal = *(w++);
+
+            uint32_t block_id = *(w++);
+
+            vtn_add_case(b, swtch, break_block, block_id, literal, is_default);
+            is_default = false;
+         }
 
          /* Now, we go through and walk the blocks.  While we walk through
           * the blocks, we also gather the much-needed fall-through