llvmpipe: try to be sensible about whether to branch after mask updates

Don't branch more than once in quick succession.  Don't branch at the
end of the shader.

3 files changed, 14 insertions, 6 deletions

diff --git a/src/gallium/auxiliary/gallivm/lp_bld_flow.c b/src/gallium/auxiliary/gallivm/lp_bld_flow.c
index cd5fbc2463..1ec33c742e 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_flow.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_flow.c
@@ -450,7 +450,7 @@ lp_build_flow_skip_end(struct lp_build_flow_context *flow)
 /**
  * Check if the mask predicate is zero.  If so, jump to the end of the block.
  */
-static void
+void
 lp_build_mask_check(struct lp_build_mask_context *mask)
 {
    LLVMBuilderRef builder = mask->flow->builder;
@@ -490,8 +490,6 @@ lp_build_mask_begin(struct lp_build_mask_context *mask,
    lp_build_flow_scope_begin(flow);
    lp_build_flow_scope_declare(flow, &mask->value);
    lp_build_flow_skip_begin(flow);
-
-   lp_build_mask_check(mask);
 }
 
 
@@ -505,8 +503,6 @@ lp_build_mask_update(struct lp_build_mask_context *mask,
                      LLVMValueRef value)
 {
    mask->value = LLVMBuildAnd( mask->flow->builder, mask->value, value, "");
-
-   lp_build_mask_check(mask);
 }
 
 
diff --git a/src/gallium/auxiliary/gallivm/lp_bld_flow.h b/src/gallium/auxiliary/gallivm/lp_bld_flow.h
index fffb493a93..095c781ec5 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_flow.h
+++ b/src/gallium/auxiliary/gallivm/lp_bld_flow.h
@@ -94,6 +94,9 @@ void
 lp_build_mask_update(struct lp_build_mask_context *mask,
                      LLVMValueRef value);
 
+void
+lp_build_mask_check(struct lp_build_mask_context *mask);
+
 LLVMValueRef
 lp_build_mask_end(struct lp_build_mask_context *mask);
 
diff --git a/src/gallium/auxiliary/gallivm/lp_bld_tgsi_soa.c b/src/gallium/auxiliary/gallivm/lp_bld_tgsi_soa.c
index 441aebae29..03020a62f8 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_tgsi_soa.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_tgsi_soa.c
@@ -959,8 +959,13 @@ emit_kil(
       }
    }
 
-   if(mask)
+   if(mask) {
       lp_build_mask_update(bld->mask, mask);
+
+      /* XXX: figure out if we are at the end of the shader and skip this:
+       */
+      lp_build_mask_check(bld->mask);
+   }
 }
 
 
@@ -987,6 +992,10 @@ emit_kilp(struct lp_build_tgsi_soa_context *bld,
    }
 
    lp_build_mask_update(bld->mask, mask);
+
+   /* XXX: figure out if we are at the end of the shader and skip this:
+    */
+   lp_build_mask_check(bld->mask);
 }
 
 static void