From 50c53376df2ca965e69e65a9c876bd667faf837c Mon Sep 17 00:00:00 2001
From: Zack Buhman <zack@buhman.org>
Date: Mon, 20 Oct 2025 20:55:04 -0500
Subject: [PATCH] assembler/fs: allow more concise assembly

---
 drm/Makefile                   |  3 +++
 regs/assembler/fs/emitter.py   | 20 +++++++++++++-------
 regs/assembler/fs/validator.py |  2 +-
 3 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/drm/Makefile b/drm/Makefile
index a3c5ae2..3c00943 100644
--- a/drm/Makefile
+++ b/drm/Makefile
@@ -12,6 +12,9 @@ LDFLAGS += $(shell pkg-config --libs libdrm) -lm
 %.vs.inc: %.vs.asm
 	PYTHONPATH=../regs/ python -m assembler.vs $< > $@
 
+%.fs.inc: %.fs.asm
+	PYTHONPATH=../regs/ python -m assembler.fs $< > $@
+
 clean:
 	find . -type f ! -name "*.*" -delete
 
diff --git a/regs/assembler/fs/emitter.py b/regs/assembler/fs/emitter.py
index 49dee47..fa6d3ce 100644
--- a/regs/assembler/fs/emitter.py
+++ b/regs/assembler/fs/emitter.py
@@ -72,8 +72,10 @@ US_FC_ADDR = parse_register("US_FC_ADDR")
 
 def emit_alpha_op(code, alpha_op):
     # dest
-    US_CMN_INST.ALPHA_WMASK(code, alpha_op.dest.wmask.value)
-    US_CMN_INST.ALPHA_OMASK(code, alpha_op.dest.omask.value)
+    if alpha_op.dest.wmask is not None:
+        US_CMN_INST.ALPHA_WMASK(code, alpha_op.dest.wmask.value)
+    if alpha_op.dest.omask is not None:
+        US_CMN_INST.ALPHA_OMASK(code, alpha_op.dest.omask.value)
 
     # opcode
     US_ALU_ALPHA_INST.ALPHA_OP(code, alpha_op.opcode.value)
@@ -105,8 +107,10 @@ def emit_alpha_op(code, alpha_op):
 
 def emit_rgb_op(code, rgb_op):
     # dest
-    US_CMN_INST.RGB_WMASK(code, rgb_op.dest.wmask.value)
-    US_CMN_INST.RGB_OMASK(code, rgb_op.dest.omask.value)
+    if rgb_op.dest.wmask is not None:
+        US_CMN_INST.RGB_WMASK(code, rgb_op.dest.wmask.value)
+    if rgb_op.dest.omask is not None:
+        US_CMN_INST.RGB_OMASK(code, rgb_op.dest.omask.value)
 
     # opcode
     US_ALU_RGBA_INST.RGB_OP(code, rgb_op.opcode.value)
@@ -150,7 +154,7 @@ def emit_addr(code, addr):
         if src is not None:
             is_const = int(src.type is SrcAddrType.const)
             is_float = int(src.type is SrcAddrType.float)
-            ADDR(code, (is_float << 7) | addr.alpha.src0.value)
+            ADDR(code, (is_float << 7) | src.value)
             ADDR_CONST(code, is_const)
         else:
             ADDR(code, (1 << 7) | 0)
@@ -165,5 +169,7 @@ def emit_instruction(code, ins):
     US_CMN_INST.TEX_SEM_WAIT(code, int(ins.tex_sem_wait))
 
     emit_addr(code, ins.addr)
-    emit_alpha_op(code, ins.alpha_op)
-    emit_rgb_op(code, ins.rgb_op)
+    if ins.alpha_op is not None:
+        emit_alpha_op(code, ins.alpha_op)
+    if ins.rgb_op is not None:
+        emit_rgb_op(code, ins.rgb_op)
diff --git a/regs/assembler/fs/validator.py b/regs/assembler/fs/validator.py
index 6944f70..67e02d5 100644
--- a/regs/assembler/fs/validator.py
+++ b/regs/assembler/fs/validator.py
@@ -398,7 +398,7 @@ def validate_instruction_operation_dest(dest_addr_swizzles, mask_lookup, type_cl
             assert False, dest
     if len(addrs) > 1:
         raise ValidatorError(f"too many destination addresses", operation.dest_addr_swizzles[-1].addr_identifier)
-    addrd, = addrs
+    addrd, = addrs if addrs else [0]
     return type_cls(
         addrd=addrd,
         wmask=wmask,