gallivm,llvmpipe: handle TXF (texelFetch) instruction, including offsets

This also adds some code to handle per-quad lods for more than 4-wide fetches,
because otherwise I'd have to integrate the texelFetch function into
the splitting stuff... (but it is not used yet outside texelFetch).
passes piglit fs-texelFetch-2D, fails fs-texelFetchOffset-2D due to I believe
a test error (results are undefined for out-of-bounds fetches, we return
whatever is at offset 0, whereas the test expects [0,0,0,1]).
Texel offsets are only handled by texelFetch for now, though the interface
can handle it for everything.

Reviewed-by: José Fonseca <[email protected]>

2 files changed, 9 insertions, 4 deletions

diff --git a/src/gallium/drivers/llvmpipe/lp_screen.c b/src/gallium/drivers/llvmpipe/lp_screen.c
index e81c44151bb..5ff8024a223 100644
--- a/src/gallium/drivers/llvmpipe/lp_screen.c
+++ b/src/gallium/drivers/llvmpipe/lp_screen.c
@@ -175,9 +175,11 @@ llvmpipe_get_param(struct pipe_screen *screen, enum pipe_cap param)
       return 0;
    case PIPE_CAP_SCALED_RESOLVE:
       return 0;
+   /* this is a lie could support arbitrary large offsets */
    case PIPE_CAP_MIN_TEXEL_OFFSET:
+      return -8;
    case PIPE_CAP_MAX_TEXEL_OFFSET:
-      return 0;
+      return 7;
    case PIPE_CAP_CONDITIONAL_RENDER:
       return 1;
    case PIPE_CAP_TEXTURE_BARRIER:
diff --git a/src/gallium/drivers/llvmpipe/lp_tex_sample.c b/src/gallium/drivers/llvmpipe/lp_tex_sample.c
index 1c5c009b556..0bd5c4aa050 100644
--- a/src/gallium/drivers/llvmpipe/lp_tex_sample.c
+++ b/src/gallium/drivers/llvmpipe/lp_tex_sample.c
@@ -176,9 +176,10 @@ static void
 lp_llvm_sampler_soa_emit_fetch_texel(const struct lp_build_sampler_soa *base,
                                      struct gallivm_state *gallivm,
                                      struct lp_type type,
+                                     boolean is_fetch,
                                      unsigned unit,
-                                     unsigned num_coords,
                                      const LLVMValueRef *coords,
+                                     const LLVMValueRef *offsets,
                                      const struct lp_derivatives *derivs,
                                      LLVMValueRef lod_bias, /* optional */
                                      LLVMValueRef explicit_lod, /* optional */
@@ -189,7 +190,7 @@ lp_llvm_sampler_soa_emit_fetch_texel(const struct lp_build_sampler_soa *base,
    assert(unit < PIPE_MAX_SAMPLERS);
    
    if (LP_PERF & PERF_NO_TEX) {
-      lp_build_sample_nop(gallivm, type, num_coords, coords, texel);
+      lp_build_sample_nop(gallivm, type, coords, texel);
       return;
    }
 
@@ -197,8 +198,10 @@ lp_llvm_sampler_soa_emit_fetch_texel(const struct lp_build_sampler_soa *base,
                        &sampler->dynamic_state.static_state[unit],
                        &sampler->dynamic_state.base,
                        type,
+                       is_fetch,
                        unit,
-                       num_coords, coords,
+                       coords,
+                       offsets,
                        derivs,
                        lod_bias, explicit_lod,
                        texel);