From 3d7a88674f9eb3320eeff511968f041426e25023 Mon Sep 17 00:00:00 2001
From: José Fonseca <jfonseca@vmware.com>
Date: Fri, 21 Aug 2009 13:49:10 +0100
Subject: llvmpipe: Early depth testing.

---
 src/gallium/drivers/llvmpipe/lp_bld_flow.c | 84 ++++++++++++++++++++++++++++++
 1 file changed, 84 insertions(+)

(limited to 'src/gallium/drivers/llvmpipe/lp_bld_flow.c')

diff --git a/src/gallium/drivers/llvmpipe/lp_bld_flow.c b/src/gallium/drivers/llvmpipe/lp_bld_flow.c
index 5fc85a19b8..d94af0dea4 100644
--- a/src/gallium/drivers/llvmpipe/lp_bld_flow.c
+++ b/src/gallium/drivers/llvmpipe/lp_bld_flow.c
@@ -31,9 +31,93 @@
  * @author Jose Fonseca <jfonseca@vmware.com>
  */
 
+#include "util/u_debug.h"
+
+#include "lp_bld_type.h"
 #include "lp_bld_flow.h"
 
 
+void
+lp_build_mask_begin(struct lp_build_mask_context *mask,
+                    LLVMBuilderRef builder,
+                    union lp_type type,
+                    LLVMValueRef value)
+{
+   memset(mask, 0, sizeof *mask);
+
+   mask->builder = builder;
+   mask->reg_type = LLVMIntType(type.width * type.length);
+   mask->value = value;
+}
+
+
+void
+lp_build_mask_update(struct lp_build_mask_context *mask,
+                     LLVMValueRef value)
+{
+
+   LLVMValueRef cond;
+   LLVMBasicBlockRef current_block;
+   LLVMBasicBlockRef next_block;
+   LLVMBasicBlockRef new_block;
+
+   if(mask->value)
+      mask->value = LLVMBuildAnd(mask->builder, mask->value, value, "");
+   else
+      mask->value = value;
+
+   cond = LLVMBuildICmp(mask->builder,
+                        LLVMIntEQ,
+                        LLVMBuildBitCast(mask->builder, mask->value, mask->reg_type, ""),
+                        LLVMConstNull(mask->reg_type),
+                        "");
+
+   current_block = LLVMGetInsertBlock(mask->builder);
+
+   if(!mask->skip_block) {
+      LLVMValueRef function = LLVMGetBasicBlockParent(current_block);
+      mask->skip_block = LLVMAppendBasicBlock(function, "skip");
+
+      mask->phi = LLVMBuildPhi(mask->builder, LLVMTypeOf(mask->value), "");
+   }
+
+   next_block = LLVMGetNextBasicBlock(current_block);
+   assert(next_block);
+   if(next_block) {
+      new_block = LLVMInsertBasicBlock(next_block, "");
+   }
+   else {
+      LLVMValueRef function = LLVMGetBasicBlockParent(current_block);
+      new_block = LLVMAppendBasicBlock(function, "");
+   }
+
+   LLVMAddIncoming(mask->phi, &mask->value, &current_block, 1);
+   LLVMBuildCondBr(mask->builder, cond, mask->skip_block, new_block);
+
+   LLVMPositionBuilderAtEnd(mask->builder, new_block);
+}
+
+
+LLVMValueRef
+lp_build_mask_end(struct lp_build_mask_context *mask)
+{
+   if(mask->skip_block) {
+      LLVMBasicBlockRef current_block = LLVMGetInsertBlock(mask->builder);
+
+      LLVMAddIncoming(mask->phi, &mask->value, &current_block, 1);
+      LLVMBuildBr(mask->builder, mask->skip_block);
+
+      LLVMPositionBuilderAtEnd(mask->builder, mask->skip_block);
+
+      mask->value = mask->phi;
+      mask->phi = NULL;
+      mask->skip_block = NULL;
+   }
+
+   return mask->value;
+}
+
+
 
 void
 lp_build_loop_begin(LLVMBuilderRef builder,
-- 
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