From 06c57cb936c7a18ea6ea6738d1985cfc542182c8 Mon Sep 17 00:00:00 2001
From: neauoire <aliceffekt@gmail.com>
Date: Mon, 1 Feb 2021 14:40:27 -0800
Subject: [PATCH] Progress on status flags

---
 README.md                |  3 +--
 build.sh                 |  2 +-
 examples/core.usm        |  3 ++-
 examples/subroutines.usm | 25 +++++++++++++++++++++++++
 uxn.c                    | 14 +++++++++++---
 5 files changed, 40 insertions(+), 7 deletions(-)
 create mode 100644 examples/subroutines.usm

diff --git a/README.md b/README.md
index 9243915..3ce29ff 100644
--- a/README.md
+++ b/README.md
@@ -36,8 +36,8 @@ $01 < pointer8 >
 
 ## Mission
 
+- Carry flag?
 - Loop
-- Conditional example
 - Pointers/Literals
 - Print word to stdout
 - Draw pixel to screen
@@ -51,7 +51,6 @@ $01 < pointer8 >
 - Implement 16 bits operations
 - Jumps should be relative
 - Catch overflow/underflow
-- Implement literals like `[2]`, and `[ 2 3 ]`.
 - Audo-detect literals length.
 - SDL Layer Emulator
 - Build PPU
diff --git a/build.sh b/build.sh
index 341ae70..1df615f 100755
--- a/build.sh
+++ b/build.sh
@@ -14,5 +14,5 @@ cc -std=c89 -DDEBUG -Wall -Wno-unknown-pragmas -Wpedantic -Wshadow -Wextra -Werr
 cc -std=c89 -DDEBUG -Wall -Wno-unknown-pragmas -Wpedantic -Wshadow -Wextra -Werror=implicit-int -Werror=incompatible-pointer-types -Werror=int-conversion -Wvla -g -Og -fsanitize=address -fsanitize=undefined uxn.c -o uxn
 
 # run
-./uxnasm examples/cond.usm boot.rom
+./uxnasm examples/core.usm boot.rom
 ./uxn boot.rom
diff --git a/examples/core.usm b/examples/core.usm
index 79a0434..3b9ccf5 100644
--- a/examples/core.usm
+++ b/examples/core.usm
@@ -1,3 +1,4 @@
 < core >
 
-+12 -34
\ No newline at end of file
++12 +34 ADD
+
diff --git a/examples/subroutines.usm b/examples/subroutines.usm
new file mode 100644
index 0000000..bee09c1
--- /dev/null
+++ b/examples/subroutines.usm
@@ -0,0 +1,25 @@
+< subroutines >
+
+:begin
+  .addall JSR ADD ADD
+  +06 EQU .isequal JSR
+  BRK
+
+:add1
+  +01 RTS
+
+:add2
+  +02 RTS
+
+:add3
+  +03 RTS
+
+:addall
+  .add1 JSR
+  .add2 JSR
+  .add3 JSR
+  RTS
+
+:isequal
+  .addall JSR +ff
+  RTS
diff --git a/uxn.c b/uxn.c
index 55b906d..450828c 100644
--- a/uxn.c
+++ b/uxn.c
@@ -92,7 +92,7 @@ rspop(void)
 
 void op_brk() { setflag(FLAG_HALT, 1); }
 void op_rts() {	cpu.mptr = rspop(); }
-void op_lit() { cpu.literal += 1;}
+void op_lit() { cpu.literal += 1; }
 void op_drp() { spop(); }
 void op_dup() { spush(cpu.stack[cpu.sptr - 1]); }
 void op_swp() { Uint8 b = spop(), a = spop(); spush(b); spush(a); }
@@ -100,8 +100,8 @@ void op_ovr() { spush(cpu.stack[cpu.sptr - 2]); }
 void op_rot() { Uint8 c = spop(),b = spop(),a = spop(); spush(b); spush(c); spush(a); }
 void op_jmp() { cpu.mptr = spop(); }
 void op_jsr() { rspush(cpu.mptr); cpu.mptr = spop(); }
-void op_jmq() { if(getflag(FLAG_ZERO)) op_jmp(); }
-void op_jsq() { if(getflag(FLAG_ZERO)) op_jsr(); }
+void op_jmq() { if(getflag(FLAG_ZERO)){ op_jmp(); } setflag(FLAG_ZERO,0); }
+void op_jsq() { if(getflag(FLAG_ZERO)){ op_jsr(); } setflag(FLAG_ZERO,0); }
 void op_equ() { setflag(FLAG_ZERO, spop() == spop()); }
 void op_neq() { setflag(FLAG_ZERO, spop() != spop()); }
 void op_lth() {	setflag(FLAG_ZERO, spop() < spop()); }
@@ -159,6 +159,8 @@ eval()
 	}
 	if(instr < 24)
 		(*ops[instr])();
+	if(instr > 0x10)
+		setflag(FLAG_ZERO, 0);
 }
 
 void
@@ -169,6 +171,12 @@ run(void)
 		eval(cpu);
 	/* debug */
 	printf("ended @ %d  |  ", cpu.counter);
+	printf("hf: %x zf: %x cf: %x tf: %x\n",
+		getflag(FLAG_HALT),
+		getflag(FLAG_ZERO),
+		getflag(FLAG_CARRY),
+		getflag(FLAG_TRAPS));
+	printf("\n\n");
 	for(i = 0; i < 4; i++)
 		printf("%d-", (cpu.status & (1 << i)) != 0);
 	printf("\n\n");