target/s390x: Implement CONVERT UNICODE insns

Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>

1 files changed, 310 insertions, 0 deletions

diff --git a/target/s390x/mem_helper.c b/target/s390x/mem_helper.c
index 7424f7f62f..33e2694c03 100644
--- a/target/s390x/mem_helper.c
+++ b/target/s390x/mem_helper.c
@@ -2196,3 +2196,313 @@ uint32_t HELPER(mvcos)(CPUS390XState *env, uint64_t dest, uint64_t src,
 
     return cc;
 }
+
+/* Decode a Unicode character.  A return value < 0 indicates success, storing
+   the UTF-32 result into OCHAR and the input length into OLEN.  A return
+   value >= 0 indicates failure, and the CC value to be returned.  */
+typedef int (*decode_unicode_fn)(CPUS390XState *env, uint64_t addr,
+                                 uint64_t ilen, bool enh_check, uintptr_t ra,
+                                 uint32_t *ochar, uint32_t *olen);
+
+/* Encode a Unicode character.  A return value < 0 indicates success, storing
+   the bytes into ADDR and the output length into OLEN.  A return value >= 0
+   indicates failure, and the CC value to be returned.  */
+typedef int (*encode_unicode_fn)(CPUS390XState *env, uint64_t addr,
+                                 uint64_t ilen, uintptr_t ra, uint32_t c,
+                                 uint32_t *olen);
+
+static int decode_utf8(CPUS390XState *env, uint64_t addr, uint64_t ilen,
+                       bool enh_check, uintptr_t ra,
+                       uint32_t *ochar, uint32_t *olen)
+{
+    uint8_t s0, s1, s2, s3;
+    uint32_t c, l;
+
+    if (ilen < 1) {
+        return 0;
+    }
+    s0 = cpu_ldub_data_ra(env, addr, ra);
+    if (s0 <= 0x7f) {
+        /* one byte character */
+        l = 1;
+        c = s0;
+    } else if (s0 <= (enh_check ? 0xc1 : 0xbf)) {
+        /* invalid character */
+        return 2;
+    } else if (s0 <= 0xdf) {
+        /* two byte character */
+        l = 2;
+        if (ilen < 2) {
+            return 0;
+        }
+        s1 = cpu_ldub_data_ra(env, addr + 1, ra);
+        c = s0 & 0x1f;
+        c = (c << 6) | (s1 & 0x3f);
+        if (enh_check && (s1 & 0xc0) != 0x80) {
+            return 2;
+        }
+    } else if (s0 <= 0xef) {
+        /* three byte character */
+        l = 3;
+        if (ilen < 3) {
+            return 0;
+        }
+        s1 = cpu_ldub_data_ra(env, addr + 1, ra);
+        s2 = cpu_ldub_data_ra(env, addr + 2, ra);
+        c = s0 & 0x0f;
+        c = (c << 6) | (s1 & 0x3f);
+        c = (c << 6) | (s2 & 0x3f);
+        /* Fold the byte-by-byte range descriptions in the PoO into
+           tests against the complete value.  It disallows encodings
+           that could be smaller, and the UTF-16 surrogates.  */
+        if (enh_check
+            && ((s1 & 0xc0) != 0x80
+                || (s2 & 0xc0) != 0x80
+                || c < 0x1000
+                || (c >= 0xd800 && c <= 0xdfff))) {
+            return 2;
+        }
+    } else if (s0 <= (enh_check ? 0xf4 : 0xf7)) {
+        /* four byte character */
+        l = 4;
+        if (ilen < 4) {
+            return 0;
+        }
+        s1 = cpu_ldub_data_ra(env, addr + 1, ra);
+        s2 = cpu_ldub_data_ra(env, addr + 2, ra);
+        s3 = cpu_ldub_data_ra(env, addr + 3, ra);
+        c = s0 & 0x07;
+        c = (c << 6) | (s1 & 0x3f);
+        c = (c << 6) | (s2 & 0x3f);
+        c = (c << 6) | (s3 & 0x3f);
+        /* See above.  */
+        if (enh_check
+            && ((s1 & 0xc0) != 0x80
+                || (s2 & 0xc0) != 0x80
+                || (s3 & 0xc0) != 0x80
+                || c < 0x010000
+                || c > 0x10ffff)) {
+            return 2;
+        }
+    } else {
+        /* invalid character */
+        return 2;
+    }
+
+    *ochar = c;
+    *olen = l;
+    return -1;
+}
+
+static int decode_utf16(CPUS390XState *env, uint64_t addr, uint64_t ilen,
+                        bool enh_check, uintptr_t ra,
+                        uint32_t *ochar, uint32_t *olen)
+{
+    uint16_t s0, s1;
+    uint32_t c, l;
+
+    if (ilen < 2) {
+        return 0;
+    }
+    s0 = cpu_lduw_data_ra(env, addr, ra);
+    if ((s0 & 0xfc00) != 0xd800) {
+        /* one word character */
+        l = 2;
+        c = s0;
+    } else {
+        /* two word character */
+        l = 4;
+        if (ilen < 4) {
+            return 0;
+        }
+        s1 = cpu_lduw_data_ra(env, addr + 2, ra);
+        c = extract32(s0, 6, 4) + 1;
+        c = (c << 6) | (s0 & 0x3f);
+        c = (c << 10) | (s1 & 0x3ff);
+        if (enh_check && (s1 & 0xfc00) != 0xdc00) {
+            /* invalid surrogate character */
+            return 2;
+        }
+    }
+
+    *ochar = c;
+    *olen = l;
+    return -1;
+}
+
+static int decode_utf32(CPUS390XState *env, uint64_t addr, uint64_t ilen,
+                        bool enh_check, uintptr_t ra,
+                        uint32_t *ochar, uint32_t *olen)
+{
+    uint32_t c;
+
+    if (ilen < 4) {
+        return 0;
+    }
+    c = cpu_ldl_data_ra(env, addr, ra);
+    if ((c >= 0xd800 && c <= 0xdbff) || c > 0x10ffff) {
+        /* invalid unicode character */
+        return 2;
+    }
+
+    *ochar = c;
+    *olen = 4;
+    return -1;
+}
+
+static int encode_utf8(CPUS390XState *env, uint64_t addr, uint64_t ilen,
+                       uintptr_t ra, uint32_t c, uint32_t *olen)
+{
+    uint8_t d[4];
+    uint32_t l, i;
+
+    if (c <= 0x7f) {
+        /* one byte character */
+        l = 1;
+        d[0] = c;
+    } else if (c <= 0x7ff) {
+        /* two byte character */
+        l = 2;
+        d[1] = 0x80 | extract32(c, 0, 6);
+        d[0] = 0xc0 | extract32(c, 6, 5);
+    } else if (c <= 0xffff) {
+        /* three byte character */
+        l = 3;
+        d[2] = 0x80 | extract32(c, 0, 6);
+        d[1] = 0x80 | extract32(c, 6, 6);
+        d[0] = 0xe0 | extract32(c, 12, 4);
+    } else {
+        /* four byte character */
+        l = 4;
+        d[3] = 0x80 | extract32(c, 0, 6);
+        d[2] = 0x80 | extract32(c, 6, 6);
+        d[1] = 0x80 | extract32(c, 12, 6);
+        d[0] = 0xf0 | extract32(c, 18, 3);
+    }
+
+    if (ilen < l) {
+        return 1;
+    }
+    for (i = 0; i < l; ++i) {
+        cpu_stb_data_ra(env, addr + i, d[i], ra);
+    }
+
+    *olen = l;
+    return -1;
+}
+
+static int encode_utf16(CPUS390XState *env, uint64_t addr, uint64_t ilen,
+                        uintptr_t ra, uint32_t c, uint32_t *olen)
+{
+    uint16_t d0, d1;
+
+    if (c <= 0xffff) {
+        /* one word character */
+        if (ilen < 2) {
+            return 1;
+        }
+        cpu_stw_data_ra(env, addr, c, ra);
+        *olen = 2;
+    } else {
+        /* two word character */
+        if (ilen < 4) {
+            return 1;
+        }
+        d1 = 0xdc00 | extract32(c, 0, 10);
+        d0 = 0xd800 | extract32(c, 10, 6);
+        d0 = deposit32(d0, 6, 4, extract32(c, 16, 5) - 1);
+        cpu_stw_data_ra(env, addr + 0, d0, ra);
+        cpu_stw_data_ra(env, addr + 2, d1, ra);
+        *olen = 4;
+    }
+
+    return -1;
+}
+
+static int encode_utf32(CPUS390XState *env, uint64_t addr, uint64_t ilen,
+                        uintptr_t ra, uint32_t c, uint32_t *olen)
+{
+    if (ilen < 4) {
+        return 1;
+    }
+    cpu_stl_data_ra(env, addr, c, ra);
+    *olen = 4;
+    return -1;
+}
+
+static inline uint32_t convert_unicode(CPUS390XState *env, uint32_t r1,
+                                       uint32_t r2, uint32_t m3, uintptr_t ra,
+                                       decode_unicode_fn decode,
+                                       encode_unicode_fn encode)
+{
+    uint64_t dst = get_address(env, r1);
+    uint64_t dlen = get_length(env, r1 + 1);
+    uint64_t src = get_address(env, r2);
+    uint64_t slen = get_length(env, r2 + 1);
+    bool enh_check = m3 & 1;
+    int cc, i;
+
+    /* Lest we fail to service interrupts in a timely manner, limit the
+       amount of work we're willing to do.  For now, let's cap at 256.  */
+    for (i = 0; i < 256; ++i) {
+        uint32_t c, ilen, olen;
+
+        cc = decode(env, src, slen, enh_check, ra, &c, &ilen);
+        if (unlikely(cc >= 0)) {
+            break;
+        }
+        cc = encode(env, dst, dlen, ra, c, &olen);
+        if (unlikely(cc >= 0)) {
+            break;
+        }
+
+        src += ilen;
+        slen -= ilen;
+        dst += olen;
+        dlen -= olen;
+        cc = 3;
+    }
+
+    set_address(env, r1, dst);
+    set_length(env, r1 + 1, dlen);
+    set_address(env, r2, src);
+    set_length(env, r2 + 1, slen);
+
+    return cc;
+}
+
+uint32_t HELPER(cu12)(CPUS390XState *env, uint32_t r1, uint32_t r2, uint32_t m3)
+{
+    return convert_unicode(env, r1, r2, m3, GETPC(),
+                           decode_utf8, encode_utf16);
+}
+
+uint32_t HELPER(cu14)(CPUS390XState *env, uint32_t r1, uint32_t r2, uint32_t m3)
+{
+    return convert_unicode(env, r1, r2, m3, GETPC(),
+                           decode_utf8, encode_utf32);
+}
+
+uint32_t HELPER(cu21)(CPUS390XState *env, uint32_t r1, uint32_t r2, uint32_t m3)
+{
+    return convert_unicode(env, r1, r2, m3, GETPC(),
+                           decode_utf16, encode_utf8);
+}
+
+uint32_t HELPER(cu24)(CPUS390XState *env, uint32_t r1, uint32_t r2, uint32_t m3)
+{
+    return convert_unicode(env, r1, r2, m3, GETPC(),
+                           decode_utf16, encode_utf32);
+}
+
+uint32_t HELPER(cu41)(CPUS390XState *env, uint32_t r1, uint32_t r2, uint32_t m3)
+{
+    return convert_unicode(env, r1, r2, m3, GETPC(),
+                           decode_utf32, encode_utf8);
+}
+
+uint32_t HELPER(cu42)(CPUS390XState *env, uint32_t r1, uint32_t r2, uint32_t m3)
+{
+    return convert_unicode(env, r1, r2, m3, GETPC(),
+                           decode_utf32, encode_utf16);
+}