radv: fix sample id loading

The sample id is packed into bits 8-12, so adjust
things properly.

Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Signed-off-by: Dave Airlie <airlied@redhat.com>

diff --git a/src/amd/common/ac_nir_to_llvm.c b/src/amd/common/ac_nir_to_llvm.c
index 741a082..c68cb9c 100644 (file)
--- a/src/amd/common/ac_nir_to_llvm.c
+++ b/src/amd/common/ac_nir_to_llvm.c
@@ -379,6 +379,23 @@ static LLVMValueRef to_float(struct nir_to_llvm_context *ctx, LLVMValueRef v)
        return v;
 }
 
+static LLVMValueRef unpack_param(struct nir_to_llvm_context *ctx,
+                                LLVMValueRef param, unsigned rshift,
+                                unsigned bitwidth)
+{
+       LLVMValueRef value = param;
+       if (rshift)
+               value = LLVMBuildLShr(ctx->builder, value,
+                                     LLVMConstInt(ctx->i32, rshift, false), "");
+
+       if (rshift + bitwidth < 32) {
+               unsigned mask = (1 << bitwidth) - 1;
+               value = LLVMBuildAnd(ctx->builder, value,
+                                    LLVMConstInt(ctx->i32, mask, false), "");
+       }
+       return value;
+}
+
 static LLVMValueRef build_gep0(struct nir_to_llvm_context *ctx,
                               LLVMValueRef base_ptr, LLVMValueRef index)
 {
@@ -2895,7 +2912,7 @@ static void visit_intrinsic(struct nir_to_llvm_context *ctx,
                result = ctx->start_instance;
                break;
        case nir_intrinsic_load_sample_id:
-               result = ctx->ancillary;
+               result = unpack_param(ctx, ctx->ancillary, 8, 4);
                break;
        case nir_intrinsic_load_sample_pos:
                result = load_sample_pos(ctx);