gallivm: Fix trivial out-of-bounds indirection in lp_build_cube_lookup().

Courtesy of clang:

  src/gallium/auxiliary/gallivm/lp_bld_sample.c:1483:10: warning: array index of '2' indexes past the end of an array (that contains 2 elements) [-Warray-bounds]
           tmp[2] = lp_build_swizzle_aos(coord_bld, ddx_ddy[1], swizzle02);
           ^   ~
  src/gallium/auxiliary/gallivm/lp_bld_sample.c:1430:10: note: array 'tmp' declared here
           LLVMValueRef ddx_ddy[2], tmp[2], rho_vec;
           ^
  src/gallium/auxiliary/gallivm/lp_bld_sample.c:1487:56: warning: array index of '2' indexes past the end of an array (that contains 2 elements) [-Warray-bounds]
              rho_vec = lp_build_add(coord_bld, rho_vec, tmp[2]);
                                                       ^   ~
  src/gallium/auxiliary/gallivm/lp_bld_sample.c:1430:10: note: array 'tmp' declared here
           LLVMValueRef ddx_ddy[2], tmp[2], rho_vec;
           ^
  src/gallium/auxiliary/gallivm/lp_bld_sample.c:1491:56: warning: array index of '2' indexes past the end of an array (that contains 2 elements) [-Warray-bounds]
              rho_vec = lp_build_max(coord_bld, rho_vec, tmp[2]);
                                                       ^   ~
  src/gallium/auxiliary/gallivm/lp_bld_sample.c:1430:10: note: array 'tmp' declared here
           LLVMValueRef ddx_ddy[2], tmp[2], rho_vec;
           ^

diff --git a/src/gallium/auxiliary/gallivm/lp_bld_sample.c b/src/gallium/auxiliary/gallivm/lp_bld_sample.c
index 33338f6..d689c7b 100644 (file)
--- a/src/gallium/auxiliary/gallivm/lp_bld_sample.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_sample.c
@@ -1427,7 +1427,7 @@ lp_build_cube_lookup(struct lp_build_sample_context *bld,
       ar_ge_as_at = lp_build_cmp(coord_bld, PIPE_FUNC_GEQUAL, ar, maxasat);
 
       if (need_derivs) {
-         LLVMValueRef ddx_ddy[2], tmp[2], rho_vec;
+         LLVMValueRef ddx_ddy[2], tmp[3], rho_vec;
          static const unsigned char swizzle0[] = { /* no-op swizzle */
             0, LP_BLD_SWIZZLE_DONTCARE,
             LP_BLD_SWIZZLE_DONTCARE, LP_BLD_SWIZZLE_DONTCARE