Add IBM hexadecimal floating point

tgtakaoka · Oct 20, 2024 · f39bf6a · f39bf6a
1 parent 5a4afeb
commit f39bf6a
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Showing 13 changed files with 549 additions and 75 deletions.
diff --git a/cli/Makefile b/cli/Makefile
@@ -43,8 +43,8 @@ CPPFLAGS = -I../src -I../driver -MD -MF [email protected]
 
 OBJS_com = \
     fixed64.o ieee_float.o float80_base.o float80_hard.o float80_soft.o \
-    dec_float.o str_buffer.o str_scanner.o option_base.o error_reporter.o \
-    insn_base.o formatters.o value_formatter.o \
+    dec_float.o ibm_float.o str_buffer.o str_scanner.o option_base.o \
+    error_reporter.o insn_base.o formatters.o value_formatter.o \
     $(foreach a,$(ARCHS),$(OBJS_$(a))) \
     bin_memory.o bin_decoder.o bin_encoder.o intel_hex.o moto_srec.o \
     file_reader.o file_printer.o list_formatter.o text_common.o

diff --git a/cli/build.ninja b/cli/build.ninja
@@ -25,7 +25,7 @@ build asm: link asm.o $
   parsers.o reg_base.o str_buffer.o str_scanner.o symbol_store.o $
   text_common.o value.o value_formatter.o value_parser.o $
   fixed64.o ieee_float.o float80_base.o float80_hard.o float80_soft.o $
-  dec_float.o $
+  dec_float.o ibm_float.o $
   asm_cdp1802.o  reg_cdp1802.o  table_cdp1802.o  text_cdp1802.o  $
   asm_f3850.o    reg_f3850.o    table_f3850.o    text_f3850.o    $
   asm_i8048.o    reg_i8048.o    table_i8048.o    text_i8048.o    $
@@ -60,7 +60,7 @@ build dis: link dis.o $
   list_formatter.o moto_srec.o option_base.o reg_base.o str_buffer.o $
   str_scanner.o text_common.o value.o value_formatter.o $
   fixed64.o ieee_float.o float80_base.o float80_hard.o float80_soft.o $
-  dec_float.o $
+  dec_float.o ibm_float.o $
   dis_cdp1802.o  reg_cdp1802.o  table_cdp1802.o  text_cdp1802.o  $
   dis_f3850.o    reg_f3850.o    table_f3850.o    text_f3850.o    $
   dis_i8048.o    reg_i8048.o    table_i8048.o    text_i8048.o    $

diff --git a/src/ibm_float.cpp b/src/ibm_float.cpp
@@ -0,0 +1,177 @@
+/*
+ * Copyright 2024 Tadashi G. Takaoka
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "ibm_float.h"
+#include "fixed64.h"
+#include "str_buffer.h"
+
+namespace libasm {
+
+const char *__ibm_float32::str() const {
+    static char buf[16];
+    StrBuffer out{buf, sizeof(buf)};
+    const auto sig = _u32 & SIG_MASK;
+    out.hex(tag(), 2).letter('.').hex(sig, 6);
+    return buf;
+}
+
+__ibm_float32 &__ibm_float32::set(uint8_t tag, uint32_t sig) {
+    return set((static_cast<uint32_t>(tag) << TAG_POS) | (sig & SIG_MASK));
+}
+
+__ibm_float32 &__ibm_float32::set(uint32_t bits) {
+    _u32 = bits;
+    return *this;
+}
+
+Error __ibm_float32::set(const float80_t &f80) {
+    auto error = OK;
+    if (f80.isNan())
+        error = NOT_AN_EXPECTED;
+    if (f80.isInf())
+        error = OVERFLOW_RANGE;
+    if (f80.isZero() || error) {
+        _u32 = bits(f80.isNegative(), 0, 0);
+        return error;
+    }
+    fixed64_t sig;
+    // IBM float fraction is [1/16 .. 1.0)
+    // IEEE float fraction is [1.0 .. 2.0)
+    auto ieee_exp = f80.decompose(sig) + 1;  // +1 for adjust
+    ieee_exp += sig.normalize();
+    while (ieee_exp % 4) {
+        ieee_exp++;
+        sig.shift_right(1);
+    }
+    sig.round_off(MANT_DIG);
+    auto ibm_exp = ieee_exp / 4;
+    auto ibm_sig = sig.value() >> (64 - TAG_POS);  // has explicit MSB
+    if (ibm_exp >= EXP_BASE) {
+        error = OVERFLOW_RANGE;
+        ibm_exp = -EXP_BASE;  // ibm_sig = 0
+    }
+    if (ibm_exp < -EXP_BASE) {
+        ibm_exp = -EXP_BASE;
+        ibm_sig = 0;
+    }
+    _u32 = bits(f80.isNegative(), ibm_exp + EXP_BASE, ibm_sig);
+    return error;
+}
+
+uint32_t __ibm_float32::bits(bool sign, uint8_t exp, uint32_t sig) {
+    const auto tag = (sign ? SGN_MASK : 0) | exp;
+    return (static_cast<uint32_t>(tag) << TAG_POS) | (sig & SIG_MASK);
+}
+
+__ibm_float32::operator float80_t() const {
+    const auto tag = static_cast<uint16_t>(_u32 >> TAG_POS);
+    const auto sign = (tag & SGN_MASK) != 0;
+    const auto bexp = tag & EXP_MASK;
+    const auto ibm_exp = static_cast<int16_t>(bexp) - EXP_BASE;
+    const auto ibm_sig = (_u32 & SIG_MASK);
+    if (bexp == 0 && ibm_sig == 0)
+        return float80_t::zero(sign);
+    fixed64_t ieee_sig{static_cast<uint64_t>(ibm_sig) << (64 - MANT_DIG)};
+    // IBM float fraction is [1/16 .. 1.0)
+    // IEEE float fraction is [1.0 .. 2.0)
+    auto ieee_exp = ibm_exp * 4 - 1;  // -1 for adjust
+    ieee_exp += ieee_sig.normalize();
+    return float80_t::compose(sign, ieee_exp, ieee_sig);
+}
+
+const char *__ibm_float64::str() const {
+    static char buf[20];
+    StrBuffer out{buf, sizeof(buf)};
+    const auto sig = _u64 & SIG_MASK;
+    out.hex(tag(), 2)
+            .letter('.')
+            .hex(static_cast<uint32_t>(sig >> 32), 6)
+            .letter('-')
+            .hex(static_cast<uint32_t>(sig), 8);
+    return buf;
+}
+
+__ibm_float64 &__ibm_float64::set(uint8_t tag, uint64_t sig) {
+    return set((static_cast<uint64_t>(tag) << TAG_POS) | (sig & SIG_MASK));
+}
+
+__ibm_float64 &__ibm_float64::set(uint64_t bits) {
+    _u64 = bits;
+    return *this;
+}
+
+Error __ibm_float64::set(const float80_t &f80) {
+    auto error = OK;
+    if (f80.isNan())
+        error = NOT_AN_EXPECTED;
+    if (f80.isInf())
+        error = OVERFLOW_RANGE;
+    if (f80.isZero() || error) {
+        _u64 = bits(f80.isNegative(), 0, 0);
+        return error;
+    }
+    fixed64_t sig;
+    // IBM float fraction is [1/16 .. 1.0)
+    // IEEE float fraction is [1.0 .. 2.0)
+    auto ieee_exp = f80.decompose(sig) + 1;  // +1 for adjust
+    while (ieee_exp % 4) {
+        ieee_exp++;
+        sig.shift_right(1);
+    }
+    sig.round_off(MANT_DIG);
+    auto ibm_exp = ieee_exp / 4;
+    auto ibm_sig = sig.value() >> (64 - TAG_POS);  // has explicit MSB
+    if (ibm_exp >= EXP_BASE) {
+        error = OVERFLOW_RANGE;
+        ibm_exp = -EXP_BASE;  // ibm_sig = 0
+    }
+    if (ibm_exp < -EXP_BASE) {
+        ibm_exp = -EXP_BASE;
+        ibm_sig = 0;
+    }
+    _u64 = bits(f80.isNegative(), ibm_exp + EXP_BASE, ibm_sig);
+    return error;
+}
+
+uint64_t __ibm_float64::bits(bool sign, uint8_t exp, uint64_t sig) {
+    const auto tag = (sign ? SGN_MASK : 0) | exp;
+    return (static_cast<uint64_t>(tag) << TAG_POS) | (sig & SIG_MASK);
+}
+
+__ibm_float64::operator float80_t() const {
+    const auto tag = static_cast<uint16_t>(_u64 >> TAG_POS);
+    const auto sign = (tag & SGN_MASK) != 0;
+    const auto bexp = tag & EXP_MASK;
+    const auto ibm_exp = static_cast<int16_t>(bexp) - EXP_BASE;
+    const auto ibm_sig = (_u64 & SIG_MASK);
+    if (bexp == 0 && ibm_sig == 0)
+        return float80_t::zero(sign);
+    fixed64_t ieee_sig{static_cast<uint64_t>(ibm_sig) << (64 - MANT_DIG)};
+    // IBM float fraction is [1/16 .. 1.0)
+    // IEEE float fraction is [1.0 .. 2.0)
+    auto ieee_exp = ibm_exp * 4 - 1;  // -1 for adjust
+    ieee_exp += ieee_sig.normalize();
+    return float80_t::compose(sign, ieee_exp, ieee_sig);
+}
+
+}  // namespace libasm
+
+// Local Variables:
+// mode: c++
+// c-basic-offset: 4
+// tab-width: 4
+// End:
+// vim: set ft=cpp et ts=4 sw=4:
diff --git a/src/ibm_float.h b/src/ibm_float.h
@@ -0,0 +1,109 @@
+/*
+ * Copyright 2024 Tadashi G. Takaoka
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __LIBASM_IBM_FLOAT_H__
+#define __LIBASM_IBM_FLOAT_H__
+
+#include <stdint.h>
+#include "error_reporter.h"
+#include "float80.h"
+
+#define IBMF32_MAX 7.237005e+75
+#define IBMF32_MIN 5.397605e-79
+#define IBMF64_MAX 7.237005577332262114e+75
+#define IBMF64_MIN 5.397605346934027891e-79
+
+namespace libasm {
+
+struct __ibm_float32 {
+    __ibm_float32(uint8_t tag = 0, uint32_t sig = 0) { set(tag, sig); }
+    __ibm_float32(const __ibm_float32 &f32) = default;
+    __ibm_float32 &operator=(const __ibm_float32 &f32) = default;
+
+    __ibm_float32 &set(uint8_t tag, uint32_t sig);
+    __ibm_float32 &set(uint32_t bits);
+
+    Error set(const float80_t &f80);
+    explicit operator float80_t() const;
+
+    uint32_t bits() const { return _u32; }
+    uint8_t tag() const { return _u32 >> TAG_POS; }
+    static uint32_t bits(bool sign, uint8_t exp, uint32_t sig);
+
+    const char *str() const;
+
+    static constexpr auto MANT_DIG = 24;
+    static constexpr auto TAG_POS = MANT_DIG;
+    static constexpr auto SGN_MASK = UINT8_C(0x80);
+    static constexpr auto EXP_MASK = UINT8_C(0x7F);
+    static constexpr auto EXP_BASE = INT8_C(0x40);
+    static constexpr auto SIG_MASK = (UINT32_C(1) << TAG_POS) - 1;
+    static constexpr auto MSD_POS = MANT_DIG - 4;
+
+private:
+    // |sign| bexp(7) | frac(24) |
+    // sign: 1=negative
+    // bexp: biased radix 16 exponent, offset 0x40, 0=zero
+    // frac: fraction hexadecimal digits, 1/16 <= frac < 1
+    uint32_t _u32;
+};
+
+struct __ibm_float64 {
+    __ibm_float64(uint8_t tag = 0, uint64_t sig = 0) { set(tag, sig); }
+    __ibm_float64(const __ibm_float64 &f64) = default;
+    __ibm_float64 &operator=(const __ibm_float64 &f64) = default;
+
+    __ibm_float64 &set(uint8_t tag, uint64_t sig);
+    __ibm_float64 &set(uint64_t bits);
+
+    Error set(const float80_t &f80);
+    explicit operator float80_t() const;
+
+    uint64_t bits() const { return _u64; }
+    uint8_t tag() const { return _u64 >> TAG_POS; }
+    static uint64_t bits(bool sign, uint8_t exp, uint64_t sig);
+
+    const char *str() const;
+
+    static constexpr auto MANT_DIG = 56;
+    static constexpr auto TAG_POS = MANT_DIG;
+    static constexpr auto SGN_MASK = UINT8_C(0x80);
+    static constexpr auto EXP_MASK = UINT8_C(0x7F);
+    static constexpr auto EXP_BASE = INT8_C(0x40);
+    static constexpr auto SIG_MASK = (UINT64_C(1) << TAG_POS) - 1;
+    static constexpr auto MSD_POS = MANT_DIG - 4;
+
+private:
+    // |sign| bexp(7) | frac(56) |
+    // sign: 1=negative
+    // bexp: biased radix 16 exponent, offset 0x40, 0=zero
+    // frac: fraction hexadecimal digits, 1/16 <= frac < 1
+    uint64_t _u64;
+};
+
+using ibm_float32_t = __ibm_float32;
+using ibm_float64_t = __ibm_float64;
+
+}  // namespace libasm
+
+#endif
+
+// Local Variables:
+// mode: c++
+// c-basic-offset: 4
+// tab-width: 4
+// End:
+// vim: set ft=cpp et ts=4 sw=4:
diff --git a/src/ninja.rules b/src/ninja.rules
@@ -11,7 +11,8 @@ build float80_base.o:    cxx ${root}/src/float80_base.cpp
 build float80_hard.o:    cxx ${root}/src/float80_hard.cpp
 build float80_soft.o:    cxx ${root}/src/float80_soft.cpp
 build formatters.o:      cxx ${root}/src/formatters.cpp
-build ieee_float.o:       cxx ${root}/src/ieee_float.cpp
+build ibm_float.o:       cxx ${root}/src/ibm_float.cpp
+build ieee_float.o:      cxx ${root}/src/ieee_float.cpp
 build insn_base.o:       cxx ${root}/src/insn_base.cpp
 build operators.o:       cxx ${root}/src/operators.cpp
 build option_base.o:     cxx ${root}/src/option_base.cpp

diff --git a/test/Makefile b/test/Makefile
@@ -47,22 +47,22 @@ OBJS_asm  = test_asm_helper.o asm_base.o \
     config_base.o insn_base.o operators.o parsers.o reg_base.o value.o \
     value_parser.o text_common.o \
     fixed64.o ieee_float.o float80_base.o float80_hard.o float80_soft.o \
-    dec_float.o
+    dec_float.o ibm_float.o
 OBJS_dis  = test_dis_helper.o dis_base.o \
     config_base.o formatters.o insn_base.o reg_base.o value.o \
     value_formatter.o text_common.o \
     fixed64.o ieee_float.o float80_base.o float80_hard.o float80_soft.o \
-    dec_float.o
+    dec_float.o ibm_float.o
 OBJS_expr = test_expr_helper.o \
     config_base.o formatters.o insn_base.o operators.o parsers.o \
     value.o value_formatter.o value_parser.o text_common.o \
     fixed64.o ieee_float.o float80_base.o float80_hard.o float80_soft.o \
-    dec_float.o
+    dec_float.o ibm_float.o
 OBJS_gen  = gen_driver.o test_generator.o tokenized_text.o \
     config_base.o dis_base.o dis_formatter.o formatters.o insn_base.o \
     list_formatter.o reg_base.o value.o value_formatter.o text_common.o \
     fixed64.o ieee_float.o float80_base.o float80_hard.o float80_soft.o \
-    dec_float.o
+    dec_float.o ibm_float.o
 
 TEST_OBJS = $(ARCHS:%=test_asm_%.o) $(ARCHS:%=test_dis_%.o)
 EXPR_OBJS = $(EXPRS:%=test_expr_%.o)