gallivm: Simplify if/then/else implementation.

No need for for a flow stack anymore.

5 files changed, 34 insertions, 91 deletions

diff --git a/src/gallium/auxiliary/gallivm/lp_bld_flow.c b/src/gallium/auxiliary/gallivm/lp_bld_flow.c
index 22c2db8c44..ac63bd544f 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_flow.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_flow.c
@@ -62,22 +62,11 @@ struct lp_build_flow_skip
 
 
 /**
- * if/else/endif.
- */
-struct lp_build_flow_if
-{
-   LLVMValueRef condition;
-   LLVMBasicBlockRef entry_block, true_block, false_block, merge_block;
-};
-
-
-/**
  * Union of all possible flow constructs' data
  */
 union lp_build_flow_construct_data
 {
    struct lp_build_flow_skip skip;
-   struct lp_build_flow_if ifthen;
 };
 
 
@@ -468,24 +457,16 @@ lp_build_loop_end_cond(LLVMBuilderRef builder,
 
   Is built with:
 
-     LLVMValueRef x = LLVMGetUndef();  // or something else
-
-     flow = lp_build_flow_create(builder);
-
-        lp_build_flow_scope_begin(flow);
+     // x needs an alloca variable
+     x = lp_build_alloca(builder, type, "x");
 
-           // x needs a phi node
-           lp_build_flow_scope_declare(flow, &x);
 
-           lp_build_if(ctx, flow, builder, cond);
-              x = LLVMAdd(1, 2);
-           lp_build_else(ctx);
-              x = LLVMAdd(2, 3);
-           lp_build_endif(ctx);
+     lp_build_if(ctx, builder, cond);
+        LLVMBuildStore(LLVMBuildAdd(1, 2), x);
+     lp_build_else(ctx);
+        LLVMBuildStore(LLVMBuildAdd(2, 3). x);
+     lp_build_endif(ctx);
 
-        lp_build_flow_scope_end(flow);
-
-     lp_build_flow_destroy(flow);
  */
 
 
@@ -494,22 +475,14 @@ lp_build_loop_end_cond(LLVMBuilderRef builder,
  * Begin an if/else/endif construct.
  */
 void
-lp_build_if(struct lp_build_if_state *ctx,
-            struct lp_build_flow_context *flow,
+lp_build_if(struct lp_build_if_state *ifthen,
             LLVMBuilderRef builder,
             LLVMValueRef condition)
 {
    LLVMBasicBlockRef block = LLVMGetInsertBlock(builder);
-   struct lp_build_flow_if *ifthen;
-
-   memset(ctx, 0, sizeof(*ctx));
-   ctx->builder = builder;
-   ctx->flow = flow;
-
-   /* push/create new scope */
-   ifthen = &lp_build_flow_push(flow, LP_BUILD_FLOW_IF)->ifthen;
-   assert(ifthen);
 
+   memset(ifthen, 0, sizeof *ifthen);
+   ifthen->builder = builder;
    ifthen->condition = condition;
    ifthen->entry_block = block;
 
@@ -529,19 +502,13 @@ lp_build_if(struct lp_build_if_state *ctx,
  * Begin else-part of a conditional
  */
 void
-lp_build_else(struct lp_build_if_state *ctx)
+lp_build_else(struct lp_build_if_state *ifthen)
 {
-   struct lp_build_flow_context *flow = ctx->flow;
-   struct lp_build_flow_if *ifthen;
-
-   ifthen = &lp_build_flow_peek(flow, LP_BUILD_FLOW_IF)->ifthen;
-   assert(ifthen);
-
    /* create/insert false_block before the merge block */
    ifthen->false_block = LLVMInsertBasicBlock(ifthen->merge_block, "if-false-block");
 
    /* successive code goes into the else block */
-   LLVMPositionBuilderAtEnd(ctx->builder, ifthen->false_block);
+   LLVMPositionBuilderAtEnd(ifthen->builder, ifthen->false_block);
 }
 
 
@@ -549,39 +516,33 @@ lp_build_else(struct lp_build_if_state *ctx)
  * End a conditional.
  */
 void
-lp_build_endif(struct lp_build_if_state *ctx)
+lp_build_endif(struct lp_build_if_state *ifthen)
 {
-   struct lp_build_flow_context *flow = ctx->flow;
-   struct lp_build_flow_if *ifthen;
-
-   ifthen = &lp_build_flow_pop(flow, LP_BUILD_FLOW_IF)->ifthen;
-   assert(ifthen);
-
    /* Insert branch to the merge block from current block */
-   LLVMBuildBr(ctx->builder, ifthen->merge_block);
+   LLVMBuildBr(ifthen->builder, ifthen->merge_block);
 
    /***
     *** Now patch in the various branch instructions.
     ***/
 
    /* Insert the conditional branch instruction at the end of entry_block */
-   LLVMPositionBuilderAtEnd(ctx->builder, ifthen->entry_block);
+   LLVMPositionBuilderAtEnd(ifthen->builder, ifthen->entry_block);
    if (ifthen->false_block) {
       /* we have an else clause */
-      LLVMBuildCondBr(ctx->builder, ifthen->condition,
+      LLVMBuildCondBr(ifthen->builder, ifthen->condition,
                       ifthen->true_block, ifthen->false_block);
    }
    else {
       /* no else clause */
-      LLVMBuildCondBr(ctx->builder, ifthen->condition,
+      LLVMBuildCondBr(ifthen->builder, ifthen->condition,
                       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(ctx->builder, ifthen->true_block);
-      LLVMBuildBr(ctx->builder, ifthen->merge_block);
+      LLVMPositionBuilderAtEnd(ifthen->builder, ifthen->true_block);
+      LLVMBuildBr(ifthen->builder, ifthen->merge_block);
    }
    else {
       /* No else clause.
@@ -591,7 +552,7 @@ lp_build_endif(struct lp_build_if_state *ctx)
    }
 
    /* Resume building code at end of the ifthen->merge_block */
-   LLVMPositionBuilderAtEnd(ctx->builder, ifthen->merge_block);
+   LLVMPositionBuilderAtEnd(ifthen->builder, ifthen->merge_block);
 }
 
 
diff --git a/src/gallium/auxiliary/gallivm/lp_bld_flow.h b/src/gallium/auxiliary/gallivm/lp_bld_flow.h
index 403e46e52e..a4fc8d1955 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_flow.h
+++ b/src/gallium/auxiliary/gallivm/lp_bld_flow.h
@@ -130,16 +130,22 @@ lp_build_loop_end_cond(LLVMBuilderRef builder,
 
 
 
+/**
+ * if/else/endif.
+ */
 struct lp_build_if_state
 {
    LLVMBuilderRef builder;
-   struct lp_build_flow_context *flow;
+   LLVMValueRef condition;
+   LLVMBasicBlockRef entry_block;
+   LLVMBasicBlockRef true_block;
+   LLVMBasicBlockRef false_block;
+   LLVMBasicBlockRef merge_block;
 };
 
 
 void
 lp_build_if(struct lp_build_if_state *ctx,
-            struct lp_build_flow_context *flow,
             LLVMBuilderRef builder,
             LLVMValueRef condition);
 
diff --git a/src/gallium/auxiliary/gallivm/lp_bld_sample.c b/src/gallium/auxiliary/gallivm/lp_bld_sample.c
index acceae2bad..1a27a24118 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_sample.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_sample.c
@@ -925,19 +925,16 @@ lp_build_cube_lookup(struct lp_build_sample_context *bld,
    rz_pos = LLVMBuildFCmp(bld->builder, LLVMRealUGE, rz, float_bld->zero, "");
 
    {
-      struct lp_build_flow_context *flow_ctx;
       struct lp_build_if_state if_ctx;
       LLVMValueRef face_s_var;
       LLVMValueRef face_t_var;
       LLVMValueRef face_var;
 
-      flow_ctx = lp_build_flow_create(bld->builder);
-
       face_s_var = lp_build_alloca(bld->builder, bld->coord_bld.vec_type, "face_s_var");
       face_t_var = lp_build_alloca(bld->builder, bld->coord_bld.vec_type, "face_t_var");
       face_var = lp_build_alloca(bld->builder, bld->int_bld.vec_type, "face_var");
 
-      lp_build_if(&if_ctx, flow_ctx, bld->builder, arx_ge_ary_arz);
+      lp_build_if(&if_ctx, bld->builder, arx_ge_ary_arz);
       {
          /* +/- X face */
          LLVMValueRef sign = lp_build_sgn(float_bld, rx);
@@ -957,7 +954,7 @@ lp_build_cube_lookup(struct lp_build_sample_context *bld,
 
          ary_ge_arx_arz = LLVMBuildAnd(bld->builder, ary_ge_arx, ary_ge_arz, "");
 
-         lp_build_if(&if_ctx2, flow_ctx, bld->builder, ary_ge_arx_arz);
+         lp_build_if(&if_ctx2, bld->builder, ary_ge_arx_arz);
          {
             /* +/- Y face */
             LLVMValueRef sign = lp_build_sgn(float_bld, ry);
@@ -989,7 +986,6 @@ lp_build_cube_lookup(struct lp_build_sample_context *bld,
       }
 
       lp_build_endif(&if_ctx);
-      lp_build_flow_destroy(flow_ctx);
 
       *face_s = LLVMBuildLoad(bld->builder, face_s_var, "face_s");
       *face_t = LLVMBuildLoad(bld->builder, face_t_var, "face_t");
diff --git a/src/gallium/auxiliary/gallivm/lp_bld_sample_aos.c b/src/gallium/auxiliary/gallivm/lp_bld_sample_aos.c
index 1e1e3591ca..69d81ad971 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_sample_aos.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_sample_aos.c
@@ -833,12 +833,9 @@ lp_build_sample_mipmap(struct lp_build_sample_context *bld,
    if (mip_filter == PIPE_TEX_MIPFILTER_LINEAR) {
       LLVMValueRef h16_scale = LLVMConstReal(LLVMFloatType(), 256.0);
       LLVMTypeRef i32_type = LLVMIntType(32);
-      struct lp_build_flow_context *flow_ctx;
       struct lp_build_if_state if_ctx;
       LLVMValueRef need_lerp;
 
-      flow_ctx = lp_build_flow_create(builder);
-
       lod_fpart = LLVMBuildFMul(builder, lod_fpart, h16_scale, "");
       lod_fpart = LLVMBuildFPToSI(builder, lod_fpart, i32_type, "lod_fpart.fixed16");
 
@@ -847,7 +844,7 @@ lp_build_sample_mipmap(struct lp_build_sample_context *bld,
                                 lod_fpart, LLVMConstNull(i32_type),
                                 "need_lerp");
 
-      lp_build_if(&if_ctx, flow_ctx, builder, need_lerp);
+      lp_build_if(&if_ctx, builder, need_lerp);
       {
          struct lp_build_context h16_bld;
 
@@ -887,8 +884,6 @@ lp_build_sample_mipmap(struct lp_build_sample_context *bld,
          LLVMBuildStore(builder, colors0_hi, colors_hi_var);
       }
       lp_build_endif(&if_ctx);
-
-      lp_build_flow_destroy(flow_ctx);
    }
 }
 
@@ -1028,17 +1023,14 @@ lp_build_sample_aos(struct lp_build_sample_context *bld,
       /* Emit conditional to choose min image filter or mag image filter
        * depending on the lod being > 0 or <= 0, respectively.
        */
-      struct lp_build_flow_context *flow_ctx;
       struct lp_build_if_state if_ctx;
       LLVMValueRef minify;
 
-      flow_ctx = lp_build_flow_create(builder);
-
       /* minify = lod >= 0.0 */
       minify = LLVMBuildICmp(builder, LLVMIntSGE,
                              lod_ipart, int_bld->zero, "");
 
-      lp_build_if(&if_ctx, flow_ctx, builder, minify);
+      lp_build_if(&if_ctx, builder, minify);
       {
          /* Use the minification filter */
          lp_build_sample_mipmap(bld,
@@ -1057,8 +1049,6 @@ lp_build_sample_aos(struct lp_build_sample_context *bld,
                                 packed_lo, packed_hi);
       }
       lp_build_endif(&if_ctx);
-
-      lp_build_flow_destroy(flow_ctx);
    }
 
    /*
diff --git a/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c b/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c
index 3b63ac6f62..75130e1c54 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c
@@ -881,19 +881,16 @@ lp_build_sample_mipmap(struct lp_build_sample_context *bld,
    }
 
    if (mip_filter == PIPE_TEX_MIPFILTER_LINEAR) {
-      struct lp_build_flow_context *flow_ctx;
       struct lp_build_if_state if_ctx;
       LLVMValueRef need_lerp;
 
-      flow_ctx = lp_build_flow_create(builder);
-
       /* need_lerp = lod_fpart > 0 */
       need_lerp = LLVMBuildFCmp(builder, LLVMRealUGT,
                                 lod_fpart,
                                 bld->float_bld.zero,
                                 "need_lerp");
 
-      lp_build_if(&if_ctx, flow_ctx, builder, need_lerp);
+      lp_build_if(&if_ctx, builder, need_lerp);
       {
          /* sample the second mipmap level */
          lp_build_mipmap_level_sizes(bld, ilevel1,
@@ -926,8 +923,6 @@ lp_build_sample_mipmap(struct lp_build_sample_context *bld,
          }
       }
       lp_build_endif(&if_ctx);
-
-      lp_build_flow_destroy(flow_ctx);
    }
 }
 
@@ -1063,17 +1058,14 @@ lp_build_sample_general(struct lp_build_sample_context *bld,
       /* Emit conditional to choose min image filter or mag image filter
        * depending on the lod being > 0 or <= 0, respectively.
        */
-      struct lp_build_flow_context *flow_ctx;
       struct lp_build_if_state if_ctx;
       LLVMValueRef minify;
 
-      flow_ctx = lp_build_flow_create(builder);
-
       /* minify = lod >= 0.0 */
       minify = LLVMBuildICmp(builder, LLVMIntSGE,
                              lod_ipart, int_bld->zero, "");
 
-      lp_build_if(&if_ctx, flow_ctx, builder, minify);
+      lp_build_if(&if_ctx, builder, minify);
       {
          /* Use the minification filter */
          lp_build_sample_mipmap(bld, unit,
@@ -1092,8 +1084,6 @@ lp_build_sample_general(struct lp_build_sample_context *bld,
                                 texels);
       }
       lp_build_endif(&if_ctx);
-
-      lp_build_flow_destroy(flow_ctx);
    }
 
    for (chan = 0; chan < 4; ++chan) {