radeonsi: don't crash if input_usage_mask is 0 for a VS input

This will start happening with the lowered IO intrinstics and new scanning
code.

Reviewed-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
Reviewed-by: Connor Abbott <cwabbott0@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6445>

diff --git a/src/gallium/drivers/radeonsi/si_shader_llvm_vs.c b/src/gallium/drivers/radeonsi/si_shader_llvm_vs.c
index 62ec43cd1953537a4a7098010bdf9a968beeffe2..f0c93ac3264a90f889d9de301c8f44f8c4c5b18a 100644 (file)
--- a/src/gallium/drivers/radeonsi/si_shader_llvm_vs.c
+++ b/src/gallium/drivers/radeonsi/si_shader_llvm_vs.c
@@ -132,8 +132,14 @@ static void load_input_vs(struct si_shader_context *ctx, unsigned input_index, L
       return;
    }
 
-   /* Do multiple loads for special formats. */
    unsigned required_channels = util_last_bit(info->input_usage_mask[input_index]);
+   if (required_channels == 0) {
+      for (unsigned i = 0; i < 4; ++i)
+         out[i] = LLVMGetUndef(ctx->ac.f32);
+      return;
+   }
+
+   /* Do multiple loads for special formats. */
    LLVMValueRef fetches[4];
    unsigned num_fetches;
    unsigned fetch_stride;