From 6d98142eda7be693bb39e8ac229d83242f0eceab Mon Sep 17 00:00:00 2001
From: Konstantin Seurer <konstantin.seurer@gmail.com>
Date: Thu, 11 Jan 2024 10:45:14 +0100
Subject: [PATCH] gallivm: Use saturating fpto*i conversions

Matches what vkd3d-proton expects and how other hardware (AMD) behaves.

Reviewed-by: Dave Airlie <airlied@redhat.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/27019>
---
 src/gallium/auxiliary/gallivm/lp_bld_nir.c | 49 +++++++---------------
 1 file changed, 16 insertions(+), 33 deletions(-)

diff --git a/src/gallium/auxiliary/gallivm/lp_bld_nir.c b/src/gallium/auxiliary/gallivm/lp_bld_nir.c
index bed636cea5e..a47fc3b4742 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_nir.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_nir.c
@@ -644,43 +644,26 @@ do_alu_action(struct lp_build_nir_context *bld_base,
                               bld_base->dbl_bld.vec_type, "");
       break;
    case nir_op_f2i8:
-      result = LLVMBuildFPToSI(builder,
-                               src[0],
-                               bld_base->uint8_bld.vec_type, "");
-      break;
    case nir_op_f2i16:
-      result = LLVMBuildFPToSI(builder,
-                               src[0],
-                               bld_base->uint16_bld.vec_type, "");
-      break;
    case nir_op_f2i32:
-      result = LLVMBuildFPToSI(builder, src[0], bld_base->base.int_vec_type, "");
-      break;
-   case nir_op_f2u8:
-      result = LLVMBuildFPToUI(builder,
-                               src[0],
-                               bld_base->uint8_bld.vec_type, "");
-      break;
-   case nir_op_f2u16:
-      result = LLVMBuildFPToUI(builder,
-                               src[0],
-                               bld_base->uint16_bld.vec_type, "");
-      break;
-   case nir_op_f2u32:
-      result = LLVMBuildFPToUI(builder,
-                               src[0],
-                               bld_base->base.int_vec_type, "");
-      break;
    case nir_op_f2i64:
-      result = LLVMBuildFPToSI(builder,
-                               src[0],
-                               bld_base->int64_bld.vec_type, "");
-      break;
-   case nir_op_f2u64:
-      result = LLVMBuildFPToUI(builder,
-                               src[0],
-                               bld_base->uint64_bld.vec_type, "");
+   case nir_op_f2u8:
+   case nir_op_f2u16:
+   case nir_op_f2u32:
+   case nir_op_f2u64: {
+      nir_alu_type dst_type = nir_op_infos[instr->op].output_type;
+      bool is_unsigned = nir_alu_type_get_base_type(dst_type) == nir_type_uint;
+      LLVMTypeRef int_type = get_int_bld(bld_base, is_unsigned, nir_alu_type_get_type_size(dst_type))->vec_type;
+
+      char name[64];
+      char tmp[64];
+      char intrinsic[64];
+      snprintf(name, sizeof(name), "llvm.fpto%ci.sat", is_unsigned ? 'u' : 's');
+      lp_format_intrinsic(tmp, 64, name, int_type);
+      lp_format_intrinsic(intrinsic, 64, tmp, LLVMTypeOf(src[0]));
+      result = lp_build_intrinsic_unary(builder, intrinsic, int_type, src[0]);
       break;
+   }
    case nir_op_fabs:
       result = lp_build_abs(get_flt_bld(bld_base, src_bit_size[0]), src[0]);
       break;