From 83f51212c1099bf675c0ef060a9c749b19614af5 Mon Sep 17 00:00:00 2001
From: Georg Lehmann <dadschoorse@gmail.com>
Date: Sat, 20 Nov 2021 21:11:57 +0100
Subject: [PATCH] ac/llvm: Implement uclz.
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Signed-off-by: Georg Lehmann <dadschoorse@gmail.com>
Reviewed-by: Timur Kristóf <timur.kristof@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/13895>
---
 src/amd/llvm/ac_nir_to_llvm.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/amd/llvm/ac_nir_to_llvm.c b/src/amd/llvm/ac_nir_to_llvm.c
index 50dd2e0665f..e3d7a398b58 100644
--- a/src/amd/llvm/ac_nir_to_llvm.c
+++ b/src/amd/llvm/ac_nir_to_llvm.c
@@ -1086,6 +1086,14 @@ static void visit_alu(struct ac_nir_context *ctx, const nir_alu_instr *instr)
    case nir_op_ifind_msb:
       result = ac_build_imsb(&ctx->ac, src[0], ctx->ac.i32);
       break;
+  case nir_op_uclz: {
+      LLVMValueRef params[2] = {
+         src[0],
+         ctx->ac.i1false,
+      };
+      result = ac_build_intrinsic(&ctx->ac, "llvm.ctlz.i32", ctx->ac.i32, params, 2, AC_FUNC_ATTR_READNONE);
+      break;
+  }
    case nir_op_uadd_carry:
       result = emit_uint_carry(&ctx->ac, "llvm.uadd.with.overflow.i32", src[0], src[1]);
       break;