Merge branch 'llvm-cliptest-viewport'

[mesa.git] / src / gallium / auxiliary / gallivm / lp_bld_flow.c

diff --git a/src/gallium/auxiliary/gallivm/lp_bld_flow.c b/src/gallium/auxiliary/gallivm/lp_bld_flow.c
index 99a49df317c05583da7cc6eae9daf2942c3f6900..a2cee199a010c4fcfdf4fcaf81fdad1763400c8b 100644 (file)
--- a/src/gallium/auxiliary/gallivm/lp_bld_flow.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_flow.c
@@ -39,6 +39,14 @@
 
 
 /**
+ * Insert a new block, right where builder is pointing to.
+ *
+ * This is useful important not only for aesthetic reasons, but also for
+ * performance reasons, as frequently run blocks should be laid out next to
+ * each other and fall-throughs maximized.
+ *
+ * See also llvm/lib/Transforms/Scalar/BasicBlockPlacement.cpp.
+ *
  * Note: this function has no dependencies on the flow code and could
  * be used elsewhere.
  */
@@ -201,59 +209,27 @@ lp_build_loop_begin(LLVMBuilderRef builder,
                     LLVMValueRef start,
                     struct lp_build_loop_state *state)
 {
-   LLVMBasicBlockRef block = LLVMGetInsertBlock(builder);
-   LLVMValueRef function = LLVMGetBasicBlockParent(block);
+   state->block = lp_build_insert_new_block(builder, "loop_begin");
 
-   state->block = LLVMAppendBasicBlock(function, "loop");
+   state->counter_var = lp_build_alloca(builder, LLVMTypeOf(start), "loop_counter");
+
+   LLVMBuildStore(builder, start, state->counter_var);
 
    LLVMBuildBr(builder, state->block);
 
    LLVMPositionBuilderAtEnd(builder, state->block);
 
-   state->counter = LLVMBuildPhi(builder, LLVMTypeOf(start), "");
-
-   LLVMAddIncoming(state->counter, &start, &block, 1);
-
+   state->counter = LLVMBuildLoad(builder, state->counter_var, "");
 }
 
 
-void
-lp_build_loop_end(LLVMBuilderRef builder,
-                  LLVMValueRef end,
-                  LLVMValueRef step,
-                  struct lp_build_loop_state *state)
-{
-   LLVMBasicBlockRef block = LLVMGetInsertBlock(builder);
-   LLVMValueRef function = LLVMGetBasicBlockParent(block);
-   LLVMValueRef next;
-   LLVMValueRef cond;
-   LLVMBasicBlockRef after_block;
-
-   if (!step)
-      step = LLVMConstInt(LLVMTypeOf(end), 1, 0);
-
-   next = LLVMBuildAdd(builder, state->counter, step, "");
-
-   cond = LLVMBuildICmp(builder, LLVMIntNE, next, end, "");
-
-   after_block = LLVMAppendBasicBlock(function, "");
-
-   LLVMBuildCondBr(builder, cond, after_block, state->block);
-
-   LLVMAddIncoming(state->counter, &next, &block, 1);
-
-   LLVMPositionBuilderAtEnd(builder, after_block);
-}
-
 void
 lp_build_loop_end_cond(LLVMBuilderRef builder,
                        LLVMValueRef end,
                        LLVMValueRef step,
-                       int llvm_cond,
+                       LLVMIntPredicate llvm_cond,
                        struct lp_build_loop_state *state)
 {
-   LLVMBasicBlockRef block = LLVMGetInsertBlock(builder);
-   LLVMValueRef function = LLVMGetBasicBlockParent(block);
    LLVMValueRef next;
    LLVMValueRef cond;
    LLVMBasicBlockRef after_block;
@@ -263,15 +239,27 @@ lp_build_loop_end_cond(LLVMBuilderRef builder,
 
    next = LLVMBuildAdd(builder, state->counter, step, "");
 
+   LLVMBuildStore(builder, next, state->counter_var);
+
    cond = LLVMBuildICmp(builder, llvm_cond, next, end, "");
 
-   after_block = LLVMAppendBasicBlock(function, "");
+   after_block = lp_build_insert_new_block(builder, "loop_end");
 
    LLVMBuildCondBr(builder, cond, after_block, state->block);
 
-   LLVMAddIncoming(state->counter, &next, &block, 1);
-
    LLVMPositionBuilderAtEnd(builder, after_block);
+
+   state->counter = LLVMBuildLoad(builder, state->counter_var, "");
+}
+
+
+void
+lp_build_loop_end(LLVMBuilderRef builder,
+                  LLVMValueRef end,
+                  LLVMValueRef step,
+                  struct lp_build_loop_state *state)
+{
+   lp_build_loop_end_cond(builder, end, step, LLVMIntNE, state);
 }
 
 
@@ -320,7 +308,6 @@ lp_build_if(struct lp_build_if_state *ifthen,
 
    /* create endif/merge basic block for the phi functions */
    ifthen->merge_block = lp_build_insert_new_block(builder, "endif-block");
-   LLVMPositionBuilderAtEnd(builder, ifthen->merge_block);
 
    /* create/insert true_block before merge_block */
    ifthen->true_block = LLVMInsertBasicBlock(ifthen->merge_block, "if-true-block");
@@ -336,6 +323,9 @@ lp_build_if(struct lp_build_if_state *ifthen,
 void
 lp_build_else(struct lp_build_if_state *ifthen)
 {
+   /* Append an unconditional Br(anch) instruction on the true_block */
+   LLVMBuildBr(ifthen->builder, ifthen->merge_block);
+
    /* create/insert false_block before the merge block */
    ifthen->false_block = LLVMInsertBasicBlock(ifthen->merge_block, "if-false-block");
 
@@ -353,9 +343,9 @@ lp_build_endif(struct lp_build_if_state *ifthen)
    /* Insert branch to the merge block from current block */
    LLVMBuildBr(ifthen->builder, ifthen->merge_block);
 
-   /***
-    *** Now patch in the various branch instructions.
-    ***/
+   /*
+    * Now patch in the various branch instructions.
+    */
 
    /* Insert the conditional branch instruction at the end of entry_block */
    LLVMPositionBuilderAtEnd(ifthen->builder, ifthen->entry_block);
@@ -370,19 +360,6 @@ lp_build_endif(struct lp_build_if_state *ifthen)
                       ifthen->true_block, ifthen->merge_block);
    }
 
-   /* Insert branch from end of true_block to merge_block */
-   if (ifthen->false_block) {
-      /* Append an unconditional Br(anch) instruction on the true_block */
-      LLVMPositionBuilderAtEnd(ifthen->builder, ifthen->true_block);
-      LLVMBuildBr(ifthen->builder, ifthen->merge_block);
-   }
-   else {
-      /* No else clause.
-       * Note that we've already inserted the branch at the end of
-       * true_block.  See the very first LLVMBuildBr() call in this function.
-       */
-   }
-
    /* Resume building code at end of the ifthen->merge_block */
    LLVMPositionBuilderAtEnd(ifthen->builder, ifthen->merge_block);
 }