Mesa (gallium_draw_llvm): draw llvm: fix iteration for larger vertex arrays

[Zack Rusin]

Module: Mesa
Branch: gallium_draw_llvm
Commit: 1e0bf24139f6047f505b138392fc0f1d6584d6bc
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=1e0bf24139f6047f505b138392fc0f1d6584d6bc

Author: Zack Rusin <zackr at vmware.com>
Date:   Tue Apr  6 12:37:31 2010 -0400

draw llvm: fix iteration for larger vertex arrays

we were trying to store the outputs starting at the same offset we
were using for the input arrays, which was writing beyond the end of
the output array.

---

 src/gallium/auxiliary/draw/draw_llvm.c |   16 ++++++++--------
 1 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/src/gallium/auxiliary/draw/draw_llvm.c b/src/gallium/auxiliary/draw/draw_llvm.c
index 021662e..a09e2a9 100644
--- a/src/gallium/auxiliary/draw/draw_llvm.c
+++ b/src/gallium/auxiliary/draw/draw_llvm.c
@@ -17,7 +17,7 @@
 
 #include <llvm-c/Transforms/Scalar.h>
 
-#define DEBUG_STORE 0
+#define DEBUG_STORE 1
 
 static void
 init_globals(struct draw_llvm *llvm)
@@ -481,7 +481,7 @@ store_aos_array(LLVMBuilderRef builder,
                           &ind3, 1, "");
 
 #if DEBUG_STORE
-   lp_build_printf(builder, "io = %p, indexes[%d, %d, %d, %d]\n",
+   lp_build_printf(builder, "   io = %p, indexes[%d, %d, %d, %d]\n",
                    io_ptr, ind0, ind1, ind2, ind3);
 #endif
 
@@ -592,7 +592,6 @@ draw_llvm_generate(struct draw_llvm *llvm)
 
    step = LLVMConstInt(LLVMInt32Type(), max_vertices, 0);
 
-   io_itr = LLVMConstInt(LLVMInt32Type(), 0, 0);
 #if DEBUG_STORE
    lp_build_printf(builder, "start = %d, end = %d, step = %d\n",
                    start, end, step);
@@ -601,11 +600,14 @@ draw_llvm_generate(struct draw_llvm *llvm)
    {
       LLVMValueRef inputs[PIPE_MAX_SHADER_INPUTS][NUM_CHANNELS];
       LLVMValueRef aos_attribs[PIPE_MAX_SHADER_INPUTS][NUM_CHANNELS];
-      LLVMValueRef io = LLVMBuildGEP(builder, io_ptr, &io_itr, 1, "");
+      LLVMValueRef io;
       const LLVMValueRef (*ptr_aos)[NUM_CHANNELS];
+
+      io_itr = LLVMBuildSub(builder, lp_loop.counter, start, "");
+      io = LLVMBuildGEP(builder, io_ptr, &io_itr, 1, "");
 #if DEBUG_STORE
-      lp_build_printf(builder, " --- loop counter %d\n",
-                      lp_loop.counter);
+      lp_build_printf(builder, " --- io %d = %p, loop counter %d\n",
+                      io_itr, io, lp_loop.counter);
 #endif
       for (i = 0; i < NUM_CHANNELS; ++i) {
          LLVMValueRef true_index = LLVMBuildAdd(
@@ -633,8 +635,6 @@ draw_llvm_generate(struct draw_llvm *llvm)
       convert_to_aos(builder, io, outputs,
                      draw->vs.vertex_shader->info.num_outputs,
                      max_vertices);
-
-      io_itr = LLVMBuildAdd(builder, io_itr, step, "");
    }
    lp_build_loop_end_cond(builder, end, step, LLVMIntUGE, &lp_loop);