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-rwxr-xr-xhome/.bin/jrp.c273
1 files changed, 273 insertions, 0 deletions
diff --git a/home/.bin/jrp.c b/home/.bin/jrp.c
new file mode 100755
index 00000000..9317ac8e
--- /dev/null
+++ b/home/.bin/jrp.c
@@ -0,0 +1,273 @@
+#if 0
+exec cc -Wall -Wextra -pedantic $@ $0 -ledit -o $(dirname $0)/jrp
+#endif
+
+// JIT RPN calculator.
+
+#include <err.h>
+#include <histedit.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/mman.h>
+#include <sysexits.h>
+#include <unistd.h>
+
+typedef unsigned long qop;
+typedef unsigned int dop;
+
+typedef long qvalue;
+typedef int dvalue;
+typedef unsigned long uvalue;
+
+typedef qvalue *(*jitFn)(qvalue *);
+typedef void (*rtFn)(qvalue);
+
+static char *formatBin(qvalue val) {
+    static char buf[sizeof(qvalue) * 8 + 1];
+    uvalue uval = val;
+    size_t i = sizeof(buf);
+    do {
+        buf[--i] = '0' + (uval & 1);
+    } while (uval >>= 1);
+    return &buf[i];
+}
+
+static void rtPrintAscii(qvalue val) {
+    printf("%c\n", (char)val);
+}
+static void rtPrintBin(qvalue val) {
+    printf("%s\n", formatBin(val));
+}
+static void rtPrintOct(qvalue val) {
+    printf("%lo\n", val);
+}
+static void rtPrintDec(qvalue val) {
+    printf("%ld\n", val);
+}
+static void rtPrintHex(qvalue val) {
+    printf("%lx\n", val);
+}
+
+static const dop DOP_NOP  = 0x90666666; // nop
+static const dop DOP_PUSH = 0xc7c74857; // push rdi; mov rdi, strict dword 0
+static const dop DOP_DROP = 0x9066665f; // pop rdi
+static const dop DOP_DUP  = 0x90666657; // push rdi
+static const dop DOP_SWAP = 0x243c8748; // xchg rdi, [rsp]
+static const dop DOP_NEG  = 0x90dff748; // neg rdi
+static const dop DOP_ADD  = 0xc7014858; // pop rax; add rdi, rax
+static const dop DOP_QUO  = 0x90c78948; // mov rdi, rax
+static const dop DOP_REM  = 0x90d78948; // mov rdi, rdx
+static const dop DOP_NOT  = 0x90d7f748; // not rdi
+static const dop DOP_AND  = 0xc7214858; // pop rax; and rdi, rax
+static const dop DOP_OR   = 0xc7094858; // pop rax; or rdi, rax
+static const dop DOP_XOR  = 0xc7314858; // pop rax; xor rdi, rax
+
+static const qop QOP_PROL = 0x5ffc8948e5894855; // push rbp; mov rbp, rsp; mov rsp, rdi; pop rdi
+static const qop QOP_EPIL = 0x5dec8948e0894857; // push rdi; mov rax, rsp; mov rsp, rbp; pop rbp
+static const qop QOP_RET  = 0x90666666906666c3; // ret
+static const qop QOP_CRT  = 0xb848906690e58748; // xchg rsp, rbp; mov rax, strict qword 0
+static const qop QOP_CALL = 0x90665fe58748d0ff; // call rax; xchg rsp, rbp; pop rdi
+static const qop QOP_PUSH = 0xbf48906690666657; // push rdi; mov rdi, strict qword 0
+static const qop QOP_SUB  = 0x9066665f243c2948; // sub [rsp], rdi; pop rdi
+static const qop QOP_MUL  = 0x906666f8af0f4858; // pop rax; imul rdi, rax
+static const qop QOP_DIV  = 0x9066fff748994858; // pop rax; cqo; idiv rdi
+static const qop QOP_SHL  = 0x5f2424d348f98948; // mov rcx, rdi; shl qword [rsp], cl; pop rdi
+static const qop QOP_SHR  = 0x5f242cd348f98948; // mov rcx, rdi; shr qword [rsp], cl; pop rdi
+
+static int radix = 10;
+
+static struct {
+    qop *base;
+    qop *ptr;
+    dop dop;
+} code;
+
+static struct {
+    qvalue *base;
+    qvalue *limit;
+    qvalue *ptr;
+} stack;
+
+static void jitDop(dop op) {
+    if (code.dop) {
+        *code.ptr++ = (qop)op << 32 | code.dop;
+        code.dop = 0;
+    } else {
+        code.dop = op;
+    }
+}
+
+static void jitQop(qop op) {
+    if (code.dop) jitDop(DOP_NOP);
+    *code.ptr++ = op;
+}
+
+static void jitPush(qvalue imm) {
+    if ((dvalue)imm == imm) {
+        jitQop(DOP_PUSH | (qop)imm << 32);
+    } else {
+        jitQop(QOP_PUSH);
+        jitQop((qop)imm);
+    }
+}
+
+static void jitCall(rtFn fn) {
+    jitQop(QOP_CRT);
+    jitQop((qop)fn);
+    jitQop(QOP_CALL);
+}
+
+static void jitBegin(void) {
+    code.ptr = code.base;
+    jitQop(QOP_PROL);
+}
+
+static void jitEnd(void) {
+    jitQop(QOP_EPIL);
+    jitQop(QOP_RET);
+}
+
+static void jitInit(void) {
+    code.base = mmap(0, getpagesize(), PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE, -1, 0);
+    if (code.base == MAP_FAILED) err(EX_OSERR, "mmap");
+}
+
+static void stackInit(void) {
+    stack.base = mmap(0, 2 * getpagesize(), PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE, -1, 0);
+    if (stack.base == MAP_FAILED) err(EX_OSERR, "mmap");
+    stack.limit = stack.base + getpagesize() / sizeof(qvalue);
+    stack.ptr = stack.limit;
+}
+
+static void jitExec(void) {
+    int error;
+    error = mprotect(code.base, getpagesize(), PROT_READ | PROT_EXEC);
+    if (error) err(EX_OSERR, "mprotect");
+    stack.ptr = ((jitFn)code.base)(stack.ptr);
+    if (stack.ptr > stack.limit) stack.ptr = stack.limit;
+    error = mprotect(code.base, getpagesize(), PROT_READ | PROT_WRITE);
+    if (error) err(EX_OSERR, "mprotect");
+}
+
+static void jitSrc(const char *src) {
+    bool quote = false;
+    while (*src) {
+        if (quote) {
+            jitPush(*src++);
+            quote = false;
+            continue;
+        }
+
+        switch (*src) {
+            case ' ': break;
+            case 39: quote = true; break;
+            case 'B': radix = 2;   break;
+            case 'O': radix = 8;   break;
+            case 'D': radix = 10;  break;
+            case 'X': radix = 16;  break;
+            case ';': jitDop(DOP_DROP); break;
+            case ':': jitDop(DOP_DUP);  break;
+            case 92:  jitDop(DOP_SWAP); break;
+            case '_': jitDop(DOP_NEG);  break;
+            case '+': jitDop(DOP_ADD);  break;
+            case '-': jitQop(QOP_SUB);  break;
+            case '*': jitQop(QOP_MUL);  break;
+            case '/': jitQop(QOP_DIV); jitDop(DOP_QUO); break;
+            case '%': jitQop(QOP_DIV); jitDop(DOP_REM); break;
+            case '~': jitDop(DOP_NOT);  break;
+            case '&': jitDop(DOP_AND);  break;
+            case '|': jitDop(DOP_OR);   break;
+            case '^': jitDop(DOP_XOR);  break;
+            case '<': jitQop(QOP_SHL);  break;
+            case '>': jitQop(QOP_SHR);  break;
+            case ',': jitCall(rtPrintAscii); break;
+            case '.': switch (radix) {
+                case 2:  jitCall(rtPrintBin); break;
+                case 8:  jitCall(rtPrintOct); break;
+                case 10: jitCall(rtPrintDec); break;
+                case 16: jitCall(rtPrintHex); break;
+            } break;
+
+            default: {
+                char *rest;
+                qvalue val = strtol(src, &rest, radix);
+                if (rest != src) {
+                    src = rest;
+                    jitPush(val);
+                    continue;
+                }
+            }
+        }
+
+        src++;
+    }
+}
+
+static void jitDump(const char *path, FILE *file) {
+    size_t nitems = code.ptr - code.base;
+    size_t written = fwrite(code.base, sizeof(qop), nitems, file);
+    if (written < nitems) err(EX_IOERR, "%s", path);
+}
+
+static char *prompt(EditLine *el __attribute((unused))) {
+    static char buf[4096];
+    char *bufPtr = buf;
+    for (qvalue *stackPtr = stack.limit - 1; stackPtr >= stack.ptr; --stackPtr) {
+        size_t bufLen = sizeof(buf) - (bufPtr - buf) - 2;
+        switch (radix) {
+            case 2:  bufPtr += snprintf(bufPtr, bufLen, " %s", formatBin(*stackPtr)); break;
+            case 8:  bufPtr += snprintf(bufPtr, bufLen, " %lo", *stackPtr); break;
+            case 10: bufPtr += snprintf(bufPtr, bufLen, " %ld", *stackPtr); break;
+            case 16: bufPtr += snprintf(bufPtr, bufLen, " %lx", *stackPtr); break;
+        }
+    }
+    buf[0] = '[';
+    if (bufPtr == buf) bufPtr++;
+    *bufPtr++ = ']';
+    *bufPtr++ = ' ';
+    *bufPtr = 0;
+    return buf;
+}
+
+int main(int argc, char *argv[]) {
+    FILE *file = NULL;
+    char *path = getenv("JRP_DUMP");
+    if (path) {
+        file = fopen(path, "w");
+        if (!file) err(EX_CANTCREAT, "%s", path);
+    }
+
+    jitInit();
+    stackInit();
+
+    if (argc > 1) {
+        jitBegin();
+        for (int i = 1; i < argc; ++i)
+            jitSrc(argv[i]);
+        jitEnd();
+        if (file) jitDump(path, file);
+        jitExec();
+        return EX_OK;
+    }
+
+    EditLine *el = el_init(argv[0], stdin, stdout, stderr);
+    el_set(el, EL_PROMPT, prompt);
+    el_set(el, EL_SIGNAL, true);
+
+    for (;;) {
+        int count;
+        const char *line = el_gets(el, &count);
+        if (count < 0) err(EX_IOERR, "el_gets");
+        if (!line) break;
+
+        jitBegin();
+        jitSrc(line);
+        jitEnd();
+        if (file) jitDump(path, file);
+        jitExec();
+    }
+
+    el_end(el);
+    return EX_OK;
+}