From 17bb5a067a9e31ceee972f76dc8d3294c101b3aa Mon Sep 17 00:00:00 2001
From: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Date: Fri, 16 Apr 2021 20:49:23 -0400
Subject: [PATCH] agx: Add saturated integer add/subtract support

Just a flag on the regular iadd instruction.

Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Acked-by: Jason Ekstrand <jason@jlekstrand.net>
Acked-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/10582>
---
 src/asahi/compiler/agx_compile.c | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/src/asahi/compiler/agx_compile.c b/src/asahi/compiler/agx_compile.c
index d2068567df6..d9215c80e61 100644
--- a/src/asahi/compiler/agx_compile.c
+++ b/src/asahi/compiler/agx_compile.c
@@ -263,6 +263,34 @@ agx_emit_alu(agx_builder *b, nir_alu_instr *instr)
    case nir_op_ineg: return agx_iadd_to(b, dst, agx_zero(), agx_neg(s0), 0);
    case nir_op_imul: return agx_imad_to(b, dst, s0, s1, agx_zero(), 0);
 
+   case nir_op_iadd_sat:
+   {
+      agx_instr *I = agx_iadd_to(b, dst, s0, s1, 0);
+      I->saturate = true;
+      return I;
+   }
+
+   case nir_op_isub_sat:
+   {
+      agx_instr *I = agx_iadd_to(b, dst, s0, agx_neg(s1), 0);
+      I->saturate = true;
+      return I;
+   }
+
+   case nir_op_uadd_sat:
+   {
+      agx_instr *I = agx_iadd_to(b, dst, agx_abs(s0), agx_abs(s1), 0);
+      I->saturate = true;
+      return I;
+   }
+
+   case nir_op_usub_sat:
+   {
+      agx_instr *I = agx_iadd_to(b, dst, agx_abs(s0), agx_neg(agx_abs(s1)), 0);
+      I->saturate = true;
+      return I;
+   }
+
    case nir_op_fsat:
    {
       agx_instr *I = agx_fadd_to(b, dst, s0, agx_negzero());