From 5ad06de4d3820e55a2ffe53228ccd3b52f7918b8 Mon Sep 17 00:00:00 2001
From: Faith Ekstrand <faith.ekstrand@collabora.com>
Date: Mon, 30 Jan 2023 20:53:18 -0600
Subject: [PATCH] nak: Allow iadd3 to take an immediate in srcs[2]

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/24998>
---
 src/nouveau/compiler/nak_encode_sm75.rs | 26 ++++++++++++++++++-------
 src/nouveau/compiler/nak_ir.rs          |  7 +++++++
 2 files changed, 26 insertions(+), 7 deletions(-)

diff --git a/src/nouveau/compiler/nak_encode_sm75.rs b/src/nouveau/compiler/nak_encode_sm75.rs
index 089b3dbc12a..7099825189a 100644
--- a/src/nouveau/compiler/nak_encode_sm75.rs
+++ b/src/nouveau/compiler/nak_encode_sm75.rs
@@ -336,13 +336,25 @@ impl SM75Instr {
     }
 
     fn encode_iadd3(&mut self, op: &OpIAdd3) {
-        self.encode_alu(
-            0x010,
-            Some(op.dst),
-            Some(op.mod_src(0)),
-            op.mod_src(1),
-            Some(op.mod_src(2)),
-        );
+        /* TODO: This should happen as part of a legalization pass */
+        assert!(op.srcs[0].is_reg_or_zero());
+        if op.srcs[2].is_reg_or_zero() {
+            self.encode_alu(
+                0x010,
+                Some(op.dst),
+                Some(op.mod_src(0)),
+                op.mod_src(1),
+                Some(op.mod_src(2)),
+            );
+        } else {
+            self.encode_alu(
+                0x010,
+                Some(op.dst),
+                Some(op.mod_src(0)),
+                op.mod_src(2),
+                Some(op.mod_src(1)),
+            );
+        }
 
         self.set_pred_src(81..84, op.carry[0]);
         self.set_pred_src(84..87, op.carry[1]);
diff --git a/src/nouveau/compiler/nak_ir.rs b/src/nouveau/compiler/nak_ir.rs
index 50fe68f01ed..7d730788be8 100644
--- a/src/nouveau/compiler/nak_ir.rs
+++ b/src/nouveau/compiler/nak_ir.rs
@@ -277,6 +277,13 @@ impl Ref {
             Src::SSA(ssa) => Some(ssa),
         }
     }
+
+    pub fn is_reg_or_zero(&self) -> bool {
+        match self {
+            Ref::Zero | Ref::SSA(_) | Ref::Reg(_) => true,
+            Ref::Imm(_) | Ref::CBuf(_) => false,
+        }
+    }
 }
 
 impl fmt::Display for Ref {