stuff

ka/crt/fmt/doprnt.k

@@ -30,8 +30,7 @@ doprnt:
 
 .print_regular:
     ; everything below rdi is a regular character; print it
-    cmp rbx, rdi
+    b.e rbx, rdi, .check_modf
-    j.z .check_modf
 
     mov ax0, b[rbx]
     call .doput
@@ -41,29 +40,22 @@ doprnt:
 
 .check_modf:
     ; did we find a '%' ?
-    cmp b[rbx], '%'
+    ; if not, then we found fmt's null-terminator; we're done
-    j.nz .epilogue  ; no, we found fmt's null-terminator; we're done
+    b.nz b[rbx], '%', .epilogue
 
     ; we did find a modifier / '%'
     mov rax, b[rbx+1]
     add rbx, 2
 
-    cmp rax, 's'
+    b.e rax, 's', .modf_s
-    j.z .modf_s
+    b.e rax, 'c', .modf_c
-    cmp rax, 'c'
+    b.e rax, 'p', .modf_p
-    j.z .modf_c
+    b.e rax, 'x', .modf_x
-    cmp rax, 'p'
+    b.e rax, 'd', .modf_d
-    j.z .modf_p
+    b.e rax, 'o', .modf_o
-    cmp rax, 'x'
+    b.e rax, 'b', .modf_b
-    j.z .modf_x
+    b.e rax, '%', .modf_percent
-    cmp rax, 'd'
+
-    j.z .modf_d
-    cmp rax, 'o'
-    j.z .modf_o
-    cmp rax, 'b'
-    j.z .modf_b
-    cmp rax, '%'
-    j.z .modf_percent
     ; unrecognized
     jmp .bad_modifier
 

ka/crt/fmt/ltostr.k

@@ -23,14 +23,11 @@ ltostr:
     xor rx8, rx8
 
     ; make sure base is in [2, 32]
-    cmp ax2, 2
+    b.b ax2, 2, .bad
-    j.b .bad
+    b.a ax2, 36, .bad
-    cmp ax2, 36
-    j.a .bad
 
     ; deal with zero
-    test ax1, ax1
+    b.e ax1, 0, .zero
-    j.z .zero
 
     ; deal with base 10 signedness
 
@@ -45,14 +42,12 @@ ltostr:
 
     ; main loop
 .conv:
-    test ax1, ax1
+    b.e ax1, 0, .fini
-    j.z .fini
 
     mov r10, ax1
     rem r10, ax2    ; ax1 % base
 
-    cmp r10, 9      ; r10 > 9 ?
+    b.a r10, 9, .nondec      ; r10 > 9 ?
-    j.a .nondec
 
     add r10, '0'
     jmp .next

ka/crt/fmt/printf.k

@@ -33,15 +33,9 @@ nprintf:
 ;
 print:
     mov rcx, STRLEN_MAX
-
+    b.z b[ax0], 0, .1
+    prns.rep.nz ax0
 .1:
-    cmp b[ax0], 0
-    ret.z
-
-    prn b[ax0]
-    inc ax0
-    loop .1
-
     ret
 
 ;
@@ -49,11 +43,8 @@ print:
 ;
 print_n:
     mov rcx, ax1
-
+    b.z b[ax0], 0, .1
+    prns.rep.nz ax0
 .1:
-    prn b[ax0]
-    inc ax0
-    loop .1
-
     ret
 

ka/crt/fmt/strtol.k

@@ -31,14 +31,11 @@ strtoq:
     mov rdx, ax0
 
     ; make sure base is in [2, 32]
-    cmp ax1, 1
+    b.z ax1, 1, .bad
-    j.z .bad
+    b.a ax1, 36, .bad
-    cmp ax1, 36
-    j.a .bad
 
     ; empty string?
-    cmp b[rdx], 0
+    b.z b[rdx], 0, .done
-    jmp.z .done
 
 .skip_spc:
     cmp b[rdx], ' '
@@ -62,36 +59,27 @@ strtoq:
 
 .unsigned:
     ; base 0
-    test ax1, ax1
+    b.z ax1, 0, .base_0
-    jmp.z .base_0
 
     ; base prefix?
-    cmp b[rdx], '0'
+    b.nz b[rdx], '0', .main_loop
-    jmp.nz .main_loop
 
     inc rdx
+    movzx rcx, b[rdx]
 
-    ; string is "0"
+    ; "0x"/"0b" prefix
-    cmp b[rdx], 0
+    b.z rcx, 0, .done ; "0"
-    jmp.z .done
+    b.z rcx, 'x', .parsed_0x
-
+    b.z rcx, 'b', .parsed_0b
-    ; "0x" prefix
-    cmp b[rdx], 'x'
-    jmp.z .parsed_0x
-
-    ; "0b" prefix
-    cmp b[rdx], 'b'
-    jmp.z .parsed_0b
 
     ; may be octal, but we don't care
-    ; we accept "0110101010" (binary) for instance
+    ; we accept "0110101010" (despite base=2) for instance
     jmp .main_loop
 
 .parsed_0x:
     ; are we in base 16?
     ; if not, leave rax = 0 and *rdx = 'x'
-    cmp ax1, 16
+    b.nz ax1, 16, .done
-    jmp.nz .done
     ; else
     inc rdx
     jmp .main_loop
@@ -99,8 +87,7 @@ strtoq:
 .parsed_0b:
     ; are we in base 2?
     ; if not, leave rax = 0 and *rdx = 'b'
-    cmp ax1, 2
+    b.nz ax1, 2, .done
-    jmp.nz .done
     ; else
     inc rdx
     jmp .main_loop
@@ -126,7 +113,7 @@ strtoq:
     mov ax1, 8
 
 .main_loop:
-    mov rx8, b[rdx]
+    movzx rx8, b[rdx]
     inc rdx
 
     cmp rx8, '0'
@@ -148,8 +135,7 @@ strtoq:
 
 .next:
     ; too large for base?
-    cmp rx8, ax1
+    b.ae rx8, ax1, .done
-    jmp.ae .done
 
     mul rax, ax1
     add rax, rx8

ka/crt/str/strrev.k

@@ -53,8 +53,7 @@ strrev2:
 
     ; increase ax0 while decreasing ax1, performing exchanges
 .2:
-    cmp ax0, ax1
+    b.ae ax0, ax1, .3
-    j.ae .3
 
     xchg b[ax0], b[ax1]
 

ka/doskrnl.k

@@ -9,7 +9,6 @@ start:
     xor rbp, rbp
 
     call main
-
     call CMD.builtins.dir
 
     hlt
@@ -19,8 +18,7 @@ start:
     scan rax
     xpause
 
-    test rax, rax
+    b.z rax, 0, .1
-    j.z .1
 
     prn rax
     jmp .1

ka/sys/main.k

@@ -2,8 +2,9 @@
 ; See the LICENSE file in the project root for more information.
 
 PrintBootMsg:
-    mov ax0, .bootmsg
+    mov rcx, STRLEN_MAX
-    call print
+    mov rdx, .bootmsg
+    prns.rep.nz rdx
     ret
 
 .bootmsg = "Starting DOS...\n\n"

ka/usr/cmd/dir.k

@@ -5,8 +5,9 @@ CMD.builtins.dir:
 
     sub nx0, nx0        # no. of files found
 
-    mov ax0, .dirmsg
+    mov rcx, STRLEN_MAX
-    call print
+    mov rdx, .dirmsg
+    prns.rep.nz rdx
 
 .dirmsg = "Directory of C:\\\n\n"
 
@@ -22,8 +23,7 @@ CMD.builtins.dir:
     call DISK.FindNext
 
 .list:
-    test rax, rax
+    b.z rax, 0, .end
-    j.z .end
 
     ; found something
     inc nx0
@@ -34,12 +34,9 @@ CMD.builtins.dir:
     mov r11, r10
     scasb.rep.nz r10, '.'
 
-.print_file_name:
+    ; print file name
-    prn b[r11]
+    ksub rcx, r10, r11
-    inc r11
+    prns.rep r11
-
-    cmp r11, r10
-    j.b .print_file_name
 
     ; calculate where to put extension
     ksub r11, r10, .buf
@@ -47,8 +44,7 @@ CMD.builtins.dir:
 
 .ext_pad:
     ; print at least 11 non-space characters before extension
-    cmp r11, 11
+    b.ae r11, 11, .print_ext
-    j.ae .print_ext
     prn ' '
     inc r11
     jmp .ext_pad
@@ -62,21 +58,18 @@ CMD.builtins.dir:
     inc.z r10
 
 .print_ext.1:
-    cmp b[r10], 0
+    b.z b[r10], 0, .print_ext.2
-    j.z .print_ext.2
 
     ; print and decrease rcx, unless it's already 0
     prn b[r10]
     inc r10
-    test rcx, rcx
+    dec.cxnz rcx
-    dec.nz rcx
 
     jmp .print_ext.1
 
 .print_ext.2:
     ; did we print at least 4 bytes?
-    test rcx, rcx
+    j.cxz .print_bytes    ; yes, carry on
-    j.z .print_bytes    ; yes, carry on
 
     prn.rep ' '
 
@@ -109,8 +102,9 @@ CMD.builtins.dir:
     call printf
     add rsp, 8
 
-    mov ax0, .endstr2
+    mov rcx, STRLEN_MAX
-    call print
+    mov rdx, .endstr2
+    prns.rep.nz rdx
 
     pop nx0
     ret

vm/in/INOUT

@@ -10,6 +10,23 @@
 #
 prn rim
 
+#
+# Print a string to standard output (PRN)
+#
+#       COMPARE([%1], 0)
+#
+#       IF (ZF == 0) THEN
+#           PRN([%1])
+#           IF (DF == 0) THEN
+#               %1 = %1 + 1
+#           ELSE
+#               %1 = %1 - 1
+#           FI
+#       FI
+#       
+#
+prns r
+
 #
 # Scan a character from standard input (SCAN)
 #

vm/in/INSTRS

@@ -13,5 +13,5 @@ include "FLAGS"
 include "INOUT"
 include "DEBUG"
 include "STRING"
-include "KINSTRS"
+include "TERNARY"
 

vm/in/JUMPS

@@ -24,20 +24,20 @@ jmp ri
 loop ri
 
 #
-# Relative jump (BCH) instruction ("branch")
+# Conditional absolute jumps (B)
 #
-#       RIP = RIP + $1
+#       COMPARE($1, $2)
 #
-b ri
+#       IF (COND) THEN
-bch ri
+#           RIP = $3
-
-#
-# RCX-dependent relative jump (BOOP) instruction
-#
-#       IF (RCX > 0) THEN
-#           RCX = RCX - 1
-#           RIP = RIP + $1
 #       FI
 #
-boop ri
+# Sets CF, OF, ZF and SF according to the comparison's results
+#
+# This instruction is special in that the COND field specified is not evaluated
+# before the instruction is executed, but after the comparison it effectuates
+#
+# Suffixing B with the REP suffix results in undefined behavior
+#
+b rim rim ri
 

vm/in/inout.c

@@ -13,6 +13,24 @@ IMPL_START_1(prn)
 }
 IMPL_END
 
+IMPL_START_0(prns)
+{
+    uchar ch = readmemzx(ctx, R(p1->reg), 1);
+
+    COMPARE(ch, 0);
+
+    if ((flg & ZF) == 0)
+    {
+        console_putc(ctx, ch);
+
+        if (flg & DF)
+            R(p1->reg)--;
+        else
+            R(p1->reg)++;
+    }
+}
+IMPL_END
+
 IMPL_START_1(scan)
 {
     v1 = console_scankeybuf(ctx);

vm/in/jumps.c

@@ -3,9 +3,7 @@
 
 #include <in/instrs.h>
 
-//
+//----------------------------------------------------------------------------//
-// Jump instructions
-//
 
 IMPL_START_1(j)
 {
@@ -28,24 +26,16 @@ IMPL_START_1(loop)
 }
 IMPL_END;
 
-IMPL_START_1(b)
+//----------------------------------------------------------------------------//
+
+IMPL_START_3(b)
 {
-    rip += v1;
+    COMPARE(v1, v2);
+
+    if (eval_cond(ctx, ctx->cond))
+        rip = v3;
 }
 IMPL_END;
 
-IMPL_START_1(bch)
+//----------------------------------------------------------------------------//
-{
-    rip += v1;
-}
-IMPL_END;
-
-IMPL_START_1(boop)
-{
-    if (rcx > 0) {
-        rcx--;
-        rip += v1;
-    }
-}
-IMPL_END;
 

vm/in/ternary.c

@@ -8,7 +8,7 @@
 #define K_IMPL_ALU(name, expr)                                              \
 IMPL_START_3(k##name)                                                       \
 {                                                                           \
-    v1 = expr;                                                              \
+    v1 = (expr);                                                            \
 }                                                                           \
 IMPL_OUT_ZSF
 

vm/pc/arch.h

@@ -70,6 +70,9 @@ struct ctx_t
 
     // Instructions executed so far
     ulong ninstrs;
+
+    // Last COND field
+    uint cond;
 };
 
 #define R(X) ctx->rf[X]

vm/pc/decode.c

@@ -7,7 +7,8 @@
 // Read the "DECD" file before reading this code
 //
 
-static void check_param_type(ctx_t *ctx, instr_t *in, uint prm, uchar fmt, int which)
+static void check_param_type(ctx_t *ctx, instr_t *in,
+                             uint prm, uchar fmt, int which)
 {
     bool ok;
 
@@ -153,7 +154,6 @@ void decode(ctx_t *ctx)
     acc_t p3 = { 0 };
 
     bool rep = 0;
-    uint cond = 0;
     bool lock, nomore;
 
     ushort w1, w2;
@@ -172,9 +172,9 @@ void decode(ctx_t *ctx)
     nomore = !!(w1 & SUFF_NOMORE);
 
     if (w1 & SUFF_COND)
-    {
+        ctx->cond = ctx->get(ctx);
-        cond = ctx->get(ctx);
+    else
-    }
+        ctx->cond = 0;
 
     w1 &= ~(SUFF_LOCK|SUFF_NOMORE|SUFF_COND);
 
@@ -217,7 +217,7 @@ void decode(ctx_t *ctx)
                     f1, f2, f3, in->full);
         }
 
-        exec_instr(ctx, in, NULL, NULL, NULL, lock, rep, cond);
+        exec_instr(ctx, in, NULL, NULL, NULL, lock, rep);
         return;
     }
 
@@ -237,7 +237,7 @@ void decode(ctx_t *ctx)
                     f1, f2, f3, in->full);
         }
 
-        exec_instr(ctx, in, &p1, NULL, NULL, lock, rep, cond);
+        exec_instr(ctx, in, &p1, NULL, NULL, lock, rep);
         return;
     }
 
@@ -257,13 +257,13 @@ void decode(ctx_t *ctx)
                     f1, f2, f3, in->full);
         }
 
-        exec_instr(ctx, in, &p1, &p2, NULL, lock, rep, cond);
+        exec_instr(ctx, in, &p1, &p2, NULL, lock, rep);
         return;
     }
 
     check_param_type(ctx, in, in->prm3, f3, 3);
     extract_param(ctx, &p3, f3);
 
-    exec_instr(ctx, in, &p1, &p2, &p3, lock, rep, cond);
+    exec_instr(ctx, in, &p1, &p2, &p3, lock, rep);
 }
 

vm/pc/decode.h

@@ -81,14 +81,15 @@ struct instr_t
                            ulong *, ulong *, ulong *);
 };
 
+bool eval_cond(ctx_t *ctx, uint cond);
+
 void exec_instr(ctx_t *ctx,
                 instr_t *in,
                 acc_t *p1,
                 acc_t *p2,
                 acc_t *p3,
                 bool lock,
-                bool rep,
+                bool rep);
-                uint cond);
 
 void extract_param(ctx_t *ctx,
                    acc_t *p,
@@ -100,6 +101,5 @@ void dump_instr(ctx_t *ctx,
                 acc_t *p2,
                 acc_t *p3,
                 bool lock,
-                bool rep,
+                bool rep);
-                uint cond);
 

vm/pc/dump.c

@@ -13,10 +13,6 @@ char *cond_suffixes[] =
     "?"
 };
 
-#ifndef _ATT_STYLE
-#define _ATT_STYLE 0
-#endif
-
 void dump_acc(ctx_t *ctx, acc_t *p);
 
 void dump_instr(ctx_t *ctx,
@@ -25,12 +21,9 @@ void dump_instr(ctx_t *ctx,
                 acc_t *p2,
                 acc_t *p3,
                 bool lock,
-                bool rep,
+                bool rep)
-                uint cond)
 {
-/*
+    uint cond = ctx->cond;
-    trace("%03lu 0x%lX:\t", ctx->ninstrs, pc);
-*/
 
     trace("0x%lX:\t", rpc);
 

vm/pc/exec.c

@@ -2,6 +2,7 @@
 // See the LICENSE file in the project root for more information.
 
 #include <pc/arch.h>
+#include <in/arch_i.h>
 
 bool eval_cond(ctx_t *ctx, uint cond)
 {
@@ -50,8 +51,7 @@ void exec_instr(ctx_t *ctx,
                 acc_t *p2, 
                 acc_t *p3, 
                 bool lock,
-                bool rep,
+                bool rep)
-                uint cond)
 {
     bool out;
     ulong r1 = 0, r2 = 0, r3 = 0;
@@ -67,17 +67,12 @@ void exec_instr(ctx_t *ctx,
     // For REPs we evaluate the condition AFTER running the instruction,
     // in a do ... while(cond) fashion
     //
-    if (!rep && !eval_cond(ctx, cond))
+    if (ctx->cond && in->func != i_b)     // 'B' instruction is special
-    {
+        if (!rep && !eval_cond(ctx, ctx->cond))
-#ifndef NDEBUG
+            return;
-        // Say something about ignored instruction?
-        //trace("0x%lX:\n", rpc);
-#endif
-        return;
-    }
 
 #ifndef NDEBUG
-    dump_instr(ctx, in, p1, p2, p3, lock, rep, cond);
+    dump_instr(ctx, in, p1, p2, p3, lock, rep);
 #endif
 
 do_rep:
@@ -132,7 +127,7 @@ do_rep:
     if (rep)
     {
         // RCX remains untouched when condition fails
-        if (!eval_cond(ctx, cond))
+        if (!eval_cond(ctx, ctx->cond))
             return;
 
         if (rcx > 0)
@@ -145,7 +140,7 @@ do_rep:
 
 #ifndef NDEBUG
         // Show that we're REP'ing
-        dump_instr(ctx, in, p1, p2, p3, lock, rep, cond);
+        dump_instr(ctx, in, p1, p2, p3, lock, rep);
 #endif
 
         goto do_rep;