Prototyping branchless integer saturated arithmetics.

2 files changed, 174 insertions, 118 deletions

diff --git a/Math_Ext.jai b/Math_Ext.jai
new file mode 100644
index 0000000..5a02756
--- /dev/null
+++ b/Math_Ext.jai
@@ -0,0 +1,172 @@
+#import "Basic";
+#import "Compiler";
+#import "Math";
+
+#run test_math_ext();
+
+test_math_ext :: () {
+
+    set_build_options_dc(.{do_output=false});
+
+    write_strings("=====================\n", "--- Test Math_Ext ---\n");
+
+    Test_Inputs :: struct(ia: $T, ib: T, ir: T, is: bool) {
+        // t: Type;
+        a := ia;
+        b := ib;
+        r := ir;
+        s := is;
+    };
+
+/*
+    tests := Test_Inputs.[
+        // .{1, 2, 3, false},
+    ];
+
+    for * tests {
+        result, saturated := add(cast(it.t)it.a, cast(it.t)it.b);
+        assert(result == it.r && saturated == it.s, "Failed: % %\n", result, saturated);
+    }
+*/
+    
+
+    t1a := S64_MAX;
+    t1b := 0;
+    t1v, t1r := add(t1a, t1b);
+    assert(t1v == S64_MAX && t1r == false, "Failed: % %\n", t1v, t1r);
+    write_string("t1: OK\n");
+
+    // t2a := S64_MAX;
+    // t2b := 1;
+    // t2v, t2r := add(t2a, t2b);
+    // assert(t2v == S64_MAX && t2r == true, "Failed: % %\n", t2v, t2r);
+}
+
+
+add_int64 :: (x :s64, y: s64) -> s64 #dump { // TODO Comparing implementations.
+    return
+        ifx (y > 0 && x > S64_MAX - y) then S64_MAX else
+        ifx (y < 0 && x < S64_MIN - y) then S64_MIN else
+        x + y;
+}
+
+sub_int64 :: (x :s64, y :s64) -> s64 {
+    return
+        ifx (y < 0 && x > S64_MAX + y) then S64_MAX else
+        ifx (y > 0 && x < S64_MIN + y) then S64_MIN else
+        x - y;
+}
+
+add :: (value_a: s64, value_b: s64) -> result: s64, saturated: bool #dump { // TODO Comparing implementaitons using dump
+    result: s64 = ---;
+    flag: bool = ---;
+    #asm {
+        mov     d: gpr === d, 9223372036854775807;
+        mov     a: gpr === a, value_a;
+        mov     b: gpr === b, value_b;
+        add     a, b;
+        seto    flag;                  // Flag overflow.
+        mov     result, a;
+        mov     a, value_a;
+        shr     a, 63;
+        add     a, d;
+        mov     c: gpr, value_a;
+        xor     c, b;
+        xor     b, result;
+        not     b;
+        or      c, b;
+        test    c, c;
+        cmovns  result, a;
+    }
+    return result, flag;
+}
+
+/*
+// value_a: s64 = 2;
+// value_b: s64 = S64_MAX-1;
+value_a: s64 = -2;
+value_b: s64 = S64_MIN+1;
+print(">%\n", S64_MAX);
+argx :=  get_command_line_arguments();
+if argx.count > 1
+    value_a = parse_int(*argx[1]);
+if argx.count > 2
+    value_b = parse_int(*argx[2]);
+
+result: s64 = ---;
+flags: s64;// = ---;
+#asm LAHF_SAHF { // TODO Remove LAHF_SAHF it not required.
+
+    // Code from https://locklessinc.com/articles/sat_arithmetic/
+
+    
+    // value_a === b;
+    // value_b === c;
+    // add     value_a, value_b;
+    // mov     result, value_a;
+
+    // Version 1
+    // mov     b: gpr === b, value_a;
+    // mov     c: gpr === c, value_b;
+    // add     b, c;
+    // mov     result, b;
+    // seto    flags;
+    // cmovns  b, c;
+
+//        s64b sat_adds64b(s64b x, s64b y)
+//        {
+//        	u64b ux = x;
+//        	u64b uy = y;
+//        	u64b res = ux + uy;
+//        	
+//        	ux = (ux >> 63) + LONG_MAX;
+//        	
+//        	/* Force compiler to use cmovns instruction */
+//        	if ((s64b) ((ux ^ uy) | ~(uy ^ res)) >= 0)
+//        	{
+//        		res = ux;
+//        	}
+//        		
+//        	return res;
+//        }
+    // Version 2 - WORKS
+    mov     d: gpr === d, 9223372036854775807;
+    mov     a: gpr === a, value_a;
+    mov     b: gpr === b, value_b;
+    add     a, b;
+    seto    flags;                  // Flag overflow.
+    mov     result, a;
+    mov     a, value_a;
+    shr     a, 63;
+    add     a, d;
+    mov     c: gpr, value_a;
+    xor     c, b;
+    xor     b, result;
+    not     b;
+    or      c, b;
+    test    c, c;
+    cmovns  result, a;
+
+//        s64b sat_subs64b(s64b x, s64b y)
+//        {
+//        	u64b ux = x;
+//        	u64b uy = y;
+//        	u64b res = ux - uy;
+//        	
+//        	ux = (ux >> 63) + LONG_MAX;
+//        	
+//        	// Force compiler to use cmovns instruction
+//        	if ((s64b)((ux ^ uy) & (ux ^ res)) < 0)
+//        	{
+//        		res = ux;
+//        	}
+//        		
+//        	return res;
+//        }
+    // TODO Use https://godbolt.org/ to help
+	
+}
+print("% + % = %\n", value_a, value_b, result);
+print("flag: %\n", flags);
+return;
+*/
\ No newline at end of file
diff --git a/ttt.jai b/ttt.jai
index 503c418..554884a 100644
--- a/ttt.jai
+++ b/ttt.jai
@@ -474,6 +474,7 @@ update_total_times :: (db: *Database) {
     totals: []s64 = db.total_times;
     memset(totals.data, 0, NUM_WEEK_DAYS * size_of(s64));
     for db.tasks {
+        // TODO Try to use local variables instead of total sub...something... the indexes thingy.
         times : []s64 = it.times;
         totals[0] = add_int64(totals[0], times[0]);
         totals[1] = add_int64(totals[1], times[1]);
@@ -1163,121 +1164,6 @@ read_enter_confirmation :: inline (row: int, style: int, message: string) -> boo
 }
 
 main :: () {
-
-    
-    add :: (value_a: s64, value_b: s64) -> s64, bool #dump { // TODO Comparing implementaitons using dump
-        result: s64 = ---;
-        flag: bool = ---;
-        #asm {
-            mov     d: gpr === d, 9223372036854775807;
-            mov     a: gpr === a, value_a;
-            mov     b: gpr === b, value_b;
-            add     a, b;
-            seto    flag;                  // Signal overflow.
-            mov     result, a;
-            mov     a, value_a;
-            shr     a, 63;
-            add     a, d;
-            mov     c: gpr, value_a;
-            xor     c, b;
-            xor     b, result;
-            not     b;
-            or      c, b;
-            test    c, c;
-            cmovns  result, a;
-        }
-        return result, flag;
-    }
-    
-    
-    // value_a: s64 = 2;
-    // value_b: s64 = S64_MAX-1;
-    value_a: s64 = -2;
-    value_b: s64 = S64_MIN+1;
-    print(">%\n", S64_MAX);
-    argx :=  get_command_line_arguments();
-    if argx.count > 1
-        value_a = parse_int(*argx[1]);
-    if argx.count > 2
-        value_b = parse_int(*argx[2]);
-
-    result: s64 = ---;
-    flags: s64;// = ---;
-    #asm LAHF_SAHF { // TODO Remove LAHF_SAHF it not required.
-
-        // Code from https://locklessinc.com/articles/sat_arithmetic/
-
-        
-        // value_a === b;
-        // value_b === c;
-        // add     value_a, value_b;
-        // mov     result, value_a;
-
-        // Version 1
-        // mov     b: gpr === b, value_a;
-        // mov     c: gpr === c, value_b;
-        // add     b, c;
-        // mov     result, b;
-        // seto    flags;
-        // cmovns  b, c;
-
-//        s64b sat_adds64b(s64b x, s64b y)
-//        {
-//        	u64b ux = x;
-//        	u64b uy = y;
-//        	u64b res = ux + uy;
-//        	
-//        	ux = (ux >> 63) + LONG_MAX;
-//        	
-//        	/* Force compiler to use cmovns instruction */
-//        	if ((s64b) ((ux ^ uy) | ~(uy ^ res)) >= 0)
-//        	{
-//        		res = ux;
-//        	}
-//        		
-//        	return res;
-//        }
-        // Version 2 - WORKS
-        mov     d: gpr === d, 9223372036854775807;
-        mov     a: gpr === a, value_a;
-        mov     b: gpr === b, value_b;
-        add     a, b;
-        seto    flags;                  // Signal overflow.
-        mov     result, a;
-        mov     a, value_a;
-        shr     a, 63;
-        add     a, d;
-        mov     c: gpr, value_a;
-        xor     c, b;
-        xor     b, result;
-        not     b;
-        or      c, b;
-        test    c, c;
-        cmovns  result, a;
-
-//        s64b sat_subs64b(s64b x, s64b y)
-//        {
-//        	u64b ux = x;
-//        	u64b uy = y;
-//        	u64b res = ux - uy;
-//        	
-//        	ux = (ux >> 63) + LONG_MAX;
-//        	
-//        	/* Force compiler to use cmovns instruction */
-//        	if ((s64b)((ux ^ uy) & (ux ^ res)) < 0)
-//        	{
-//        		res = ux;
-//        	}
-//        		
-//        	return res;
-//        }
-        // TODO Use https://godbolt.org/ to help
-    	
-    }
-    print("% + % = %\n", value_a, value_b, result);
-    print("flag: %\n", flags);
-    return;
-    
     
     // TODO Implement signal handling and see modules/Debug.jai for examples.
     
@@ -1293,9 +1179,7 @@ main :: () {
         }
         
         home_path, success_path := get_absolute_path(home_dir); // Returns temporary memory.
-        
-
-        
+                
         if success_path == false {
             print_error("Failed to find home directory '%'.", home_dir);
             exit(1);