From 6d0bc8538bde71f99b8b3b405d6cce1cb4d90dee Mon Sep 17 00:00:00 2001
From: Zack Buhman <zack@buhman.org>
Date: Sun, 19 Oct 2025 15:31:10 -0500
Subject: [PATCH] assembler: add support for VE_SAT/ME_SAT

---
 regs/assembler/emitter.py  |  7 ++++++-
 regs/assembler/keywords.py |  2 ++
 regs/assembler/parser.py   | 16 +++++++++++++++-
 3 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/regs/assembler/emitter.py b/regs/assembler/emitter.py
index 53bbb62..d45538f 100644
--- a/regs/assembler/emitter.py
+++ b/regs/assembler/emitter.py
@@ -38,16 +38,21 @@ def emit_destination_op(dst_op: DestinationOp):
     math_inst = int(type(dst_op.opcode) is ME)
     if dst_op.macro:
         assert dst_op.opcode.value in {0, 1}
+    ve_sat = int((not math_inst) and dst_op.sat)
+    me_sat = int(math_inst and dst_op.sat)
+
     value = (
           pvs_dst.OPCODE_gen(dst_op.opcode.value)
         | pvs_dst.MATH_INST_gen(math_inst)
+        | pvs_dst.MACRO_INST_gen(int(dst_op.macro))
         | pvs_dst.REG_TYPE_gen(dst_reg_type(dst_op.type))
         | pvs_dst.OFFSET_gen(dst_op.offset)
         | pvs_dst.WE_X_gen(we_x(dst_op.write_enable))
         | pvs_dst.WE_Y_gen(we_y(dst_op.write_enable))
         | pvs_dst.WE_Z_gen(we_z(dst_op.write_enable))
         | pvs_dst.WE_W_gen(we_w(dst_op.write_enable))
-        | pvs_dst.MACRO_INST_gen(int(dst_op.macro))
+        | pvs_dst.VE_SAT_gen(ve_sat)
+        | pvs_dst.ME_SAT_gen(me_sat)
     )
     yield value
 
diff --git a/regs/assembler/keywords.py b/regs/assembler/keywords.py
index f0e6a05..3b3ae46 100644
--- a/regs/assembler/keywords.py
+++ b/regs/assembler/keywords.py
@@ -102,6 +102,7 @@ class KW(Enum):
     relative_a0 = auto()
     relative_i0 = auto()
     constant = auto()
+    saturation = auto()
 
 keywords = [
     (KW.temporary     , b"temporary"     , b"temp"),
@@ -114,6 +115,7 @@ keywords = [
     (KW.relative_a0   , b"relative_a0"   , None),
     (KW.relative_i0   , b"relative_i0"   , None),
     (KW.constant      , b"constant"      , b"const"),
+    (KW.saturation    , b"saturation"    , b"sat"),
 ]
 
 def find_keyword(b: memoryview):
diff --git a/regs/assembler/parser.py b/regs/assembler/parser.py
index 40a6c13..1c7a651 100644
--- a/regs/assembler/parser.py
+++ b/regs/assembler/parser.py
@@ -25,6 +25,7 @@ class DestinationOp:
     offset: int
     write_enable: set[int]
     opcode: Union[VE, ME]
+    sat: bool
     macro: bool
 
 @dataclass
@@ -173,8 +174,21 @@ class Parser:
         write_enable = parse_dest_write_enable(write_enable_token)
         self.consume(TT.equal, "expected equals")
         opcode = self.opcode()
+        sat = False
+        if self.match(TT.dot):
+            self.advance()
+            suffix = self.consume(TT.keyword, "expected saturation suffix")
+            if suffix.keyword is not KW.saturation:
+                raise ParserError("expected saturation suffix", token)
+            sat = True
+
         macro = False
-        return DestinationOp(destination_type, offset_value, write_enable, opcode, macro)
+        return DestinationOp(type=destination_type,
+                             offset=offset_value,
+                             write_enable=write_enable,
+                             opcode=opcode,
+                             sat=sat,
+                             macro=macro)
 
     def source_type(self):
         token = self.consume(TT.keyword, "expected source type")