target-alpha: Move floating-point helpers to fpu_helper.c.

Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>

1 files changed, 846 insertions, 0 deletions

diff --git a/target-alpha/fpu_helper.c b/target-alpha/fpu_helper.c
new file mode 100644
index 0000000000..d38521b6d8
--- /dev/null
+++ b/target-alpha/fpu_helper.c
@@ -0,0 +1,846 @@
+/*
+ *  Helpers for floating point instructions.
+ *
+ *  Copyright (c) 2007 Jocelyn Mayer
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "cpu.h"
+#include "helper.h"
+#include "softfloat.h"
+
+#define FP_STATUS (env->fp_status)
+
+
+void helper_setroundmode(CPUAlphaState *env, uint32_t val)
+{
+    set_float_rounding_mode(val, &FP_STATUS);
+}
+
+void helper_setflushzero(CPUAlphaState *env, uint32_t val)
+{
+    set_flush_to_zero(val, &FP_STATUS);
+}
+
+void helper_fp_exc_clear(CPUAlphaState *env)
+{
+    set_float_exception_flags(0, &FP_STATUS);
+}
+
+uint32_t helper_fp_exc_get(CPUAlphaState *env)
+{
+    return get_float_exception_flags(&FP_STATUS);
+}
+
+static inline void inline_fp_exc_raise(CPUAlphaState *env, void *retaddr,
+                                       uint32_t exc, uint32_t regno)
+{
+    if (exc) {
+        uint32_t hw_exc = 0;
+
+        if (exc & float_flag_invalid) {
+            hw_exc |= EXC_M_INV;
+        }
+        if (exc & float_flag_divbyzero) {
+            hw_exc |= EXC_M_DZE;
+        }
+        if (exc & float_flag_overflow) {
+            hw_exc |= EXC_M_FOV;
+        }
+        if (exc & float_flag_underflow) {
+            hw_exc |= EXC_M_UNF;
+        }
+        if (exc & float_flag_inexact) {
+            hw_exc |= EXC_M_INE;
+        }
+
+        arith_excp(env, retaddr, hw_exc, 1ull << regno);
+    }
+}
+
+/* Raise exceptions for ieee fp insns without software completion.
+   In that case there are no exceptions that don't trap; the mask
+   doesn't apply.  */
+void helper_fp_exc_raise(CPUAlphaState *env, uint32_t exc, uint32_t regno)
+{
+    inline_fp_exc_raise(env, GETPC(), exc, regno);
+}
+
+/* Raise exceptions for ieee fp insns with software completion.  */
+void helper_fp_exc_raise_s(CPUAlphaState *env, uint32_t exc, uint32_t regno)
+{
+    if (exc) {
+        env->fpcr_exc_status |= exc;
+        exc &= ~env->fpcr_exc_mask;
+        inline_fp_exc_raise(env, GETPC(), exc, regno);
+    }
+}
+
+/* Input remapping without software completion.  Handle denormal-map-to-zero
+   and trap for all other non-finite numbers.  */
+uint64_t helper_ieee_input(CPUAlphaState *env, uint64_t val)
+{
+    uint32_t exp = (uint32_t)(val >> 52) & 0x7ff;
+    uint64_t frac = val & 0xfffffffffffffull;
+
+    if (exp == 0) {
+        if (frac != 0) {
+            /* If DNZ is set flush denormals to zero on input.  */
+            if (env->fpcr_dnz) {
+                val &= 1ull << 63;
+            } else {
+                arith_excp(env, GETPC(), EXC_M_UNF, 0);
+            }
+        }
+    } else if (exp == 0x7ff) {
+        /* Infinity or NaN.  */
+        /* ??? I'm not sure these exception bit flags are correct.  I do
+           know that the Linux kernel, at least, doesn't rely on them and
+           just emulates the insn to figure out what exception to use.  */
+        arith_excp(env, GETPC(), frac ? EXC_M_INV : EXC_M_FOV, 0);
+    }
+    return val;
+}
+
+/* Similar, but does not trap for infinities.  Used for comparisons.  */
+uint64_t helper_ieee_input_cmp(CPUAlphaState *env, uint64_t val)
+{
+    uint32_t exp = (uint32_t)(val >> 52) & 0x7ff;
+    uint64_t frac = val & 0xfffffffffffffull;
+
+    if (exp == 0) {
+        if (frac != 0) {
+            /* If DNZ is set flush denormals to zero on input.  */
+            if (env->fpcr_dnz) {
+                val &= 1ull << 63;
+            } else {
+                arith_excp(env, GETPC(), EXC_M_UNF, 0);
+            }
+        }
+    } else if (exp == 0x7ff && frac) {
+        /* NaN.  */
+        arith_excp(env, GETPC(), EXC_M_INV, 0);
+    }
+    return val;
+}
+
+/* Input remapping with software completion enabled.  All we have to do
+   is handle denormal-map-to-zero; all other inputs get exceptions as
+   needed from the actual operation.  */
+uint64_t helper_ieee_input_s(CPUAlphaState *env, uint64_t val)
+{
+    if (env->fpcr_dnz) {
+        uint32_t exp = (uint32_t)(val >> 52) & 0x7ff;
+        if (exp == 0) {
+            val &= 1ull << 63;
+        }
+    }
+    return val;
+}
+
+/* F floating (VAX) */
+static uint64_t float32_to_f(float32 fa)
+{
+    uint64_t r, exp, mant, sig;
+    CPU_FloatU a;
+
+    a.f = fa;
+    sig = ((uint64_t)a.l & 0x80000000) << 32;
+    exp = (a.l >> 23) & 0xff;
+    mant = ((uint64_t)a.l & 0x007fffff) << 29;
+
+    if (exp == 255) {
+        /* NaN or infinity */
+        r = 1; /* VAX dirty zero */
+    } else if (exp == 0) {
+        if (mant == 0) {
+            /* Zero */
+            r = 0;
+        } else {
+            /* Denormalized */
+            r = sig | ((exp + 1) << 52) | mant;
+        }
+    } else {
+        if (exp >= 253) {
+            /* Overflow */
+            r = 1; /* VAX dirty zero */
+        } else {
+            r = sig | ((exp + 2) << 52);
+        }
+    }
+
+    return r;
+}
+
+static float32 f_to_float32(CPUAlphaState *env, void *retaddr, uint64_t a)
+{
+    uint32_t exp, mant_sig;
+    CPU_FloatU r;
+
+    exp = ((a >> 55) & 0x80) | ((a >> 52) & 0x7f);
+    mant_sig = ((a >> 32) & 0x80000000) | ((a >> 29) & 0x007fffff);
+
+    if (unlikely(!exp && mant_sig)) {
+        /* Reserved operands / Dirty zero */
+        dynamic_excp(env, retaddr, EXCP_OPCDEC, 0);
+    }
+
+    if (exp < 3) {
+        /* Underflow */
+        r.l = 0;
+    } else {
+        r.l = ((exp - 2) << 23) | mant_sig;
+    }
+
+    return r.f;
+}
+
+uint32_t helper_f_to_memory(uint64_t a)
+{
+    uint32_t r;
+    r =  (a & 0x00001fffe0000000ull) >> 13;
+    r |= (a & 0x07ffe00000000000ull) >> 45;
+    r |= (a & 0xc000000000000000ull) >> 48;
+    return r;
+}
+
+uint64_t helper_memory_to_f(uint32_t a)
+{
+    uint64_t r;
+    r =  ((uint64_t)(a & 0x0000c000)) << 48;
+    r |= ((uint64_t)(a & 0x003fffff)) << 45;
+    r |= ((uint64_t)(a & 0xffff0000)) << 13;
+    if (!(a & 0x00004000)) {
+        r |= 0x7ll << 59;
+    }
+    return r;
+}
+
+/* ??? Emulating VAX arithmetic with IEEE arithmetic is wrong.  We should
+   either implement VAX arithmetic properly or just signal invalid opcode.  */
+
+uint64_t helper_addf(CPUAlphaState *env, uint64_t a, uint64_t b)
+{
+    float32 fa, fb, fr;
+
+    fa = f_to_float32(env, GETPC(), a);
+    fb = f_to_float32(env, GETPC(), b);
+    fr = float32_add(fa, fb, &FP_STATUS);
+    return float32_to_f(fr);
+}
+
+uint64_t helper_subf(CPUAlphaState *env, uint64_t a, uint64_t b)
+{
+    float32 fa, fb, fr;
+
+    fa = f_to_float32(env, GETPC(), a);
+    fb = f_to_float32(env, GETPC(), b);
+    fr = float32_sub(fa, fb, &FP_STATUS);
+    return float32_to_f(fr);
+}
+
+uint64_t helper_mulf(CPUAlphaState *env, uint64_t a, uint64_t b)
+{
+    float32 fa, fb, fr;
+
+    fa = f_to_float32(env, GETPC(), a);
+    fb = f_to_float32(env, GETPC(), b);
+    fr = float32_mul(fa, fb, &FP_STATUS);
+    return float32_to_f(fr);
+}
+
+uint64_t helper_divf(CPUAlphaState *env, uint64_t a, uint64_t b)
+{
+    float32 fa, fb, fr;
+
+    fa = f_to_float32(env, GETPC(), a);
+    fb = f_to_float32(env, GETPC(), b);
+    fr = float32_div(fa, fb, &FP_STATUS);
+    return float32_to_f(fr);
+}
+
+uint64_t helper_sqrtf(CPUAlphaState *env, uint64_t t)
+{
+    float32 ft, fr;
+
+    ft = f_to_float32(env, GETPC(), t);
+    fr = float32_sqrt(ft, &FP_STATUS);
+    return float32_to_f(fr);
+}
+
+
+/* G floating (VAX) */
+static uint64_t float64_to_g(float64 fa)
+{
+    uint64_t r, exp, mant, sig;
+    CPU_DoubleU a;
+
+    a.d = fa;
+    sig = a.ll & 0x8000000000000000ull;
+    exp = (a.ll >> 52) & 0x7ff;
+    mant = a.ll & 0x000fffffffffffffull;
+
+    if (exp == 2047) {
+        /* NaN or infinity */
+        r = 1; /* VAX dirty zero */
+    } else if (exp == 0) {
+        if (mant == 0) {
+            /* Zero */
+            r = 0;
+        } else {
+            /* Denormalized */
+            r = sig | ((exp + 1) << 52) | mant;
+        }
+    } else {
+        if (exp >= 2045) {
+            /* Overflow */
+            r = 1; /* VAX dirty zero */
+        } else {
+            r = sig | ((exp + 2) << 52);
+        }
+    }
+
+    return r;
+}
+
+static float64 g_to_float64(CPUAlphaState *env, void *retaddr, uint64_t a)
+{
+    uint64_t exp, mant_sig;
+    CPU_DoubleU r;
+
+    exp = (a >> 52) & 0x7ff;
+    mant_sig = a & 0x800fffffffffffffull;
+
+    if (!exp && mant_sig) {
+        /* Reserved operands / Dirty zero */
+        dynamic_excp(env, retaddr, EXCP_OPCDEC, 0);
+    }
+
+    if (exp < 3) {
+        /* Underflow */
+        r.ll = 0;
+    } else {
+        r.ll = ((exp - 2) << 52) | mant_sig;
+    }
+
+    return r.d;
+}
+
+uint64_t helper_g_to_memory(uint64_t a)
+{
+    uint64_t r;
+    r =  (a & 0x000000000000ffffull) << 48;
+    r |= (a & 0x00000000ffff0000ull) << 16;
+    r |= (a & 0x0000ffff00000000ull) >> 16;
+    r |= (a & 0xffff000000000000ull) >> 48;
+    return r;
+}
+
+uint64_t helper_memory_to_g(uint64_t a)
+{
+    uint64_t r;
+    r =  (a & 0x000000000000ffffull) << 48;
+    r |= (a & 0x00000000ffff0000ull) << 16;
+    r |= (a & 0x0000ffff00000000ull) >> 16;
+    r |= (a & 0xffff000000000000ull) >> 48;
+    return r;
+}
+
+uint64_t helper_addg(CPUAlphaState *env, uint64_t a, uint64_t b)
+{
+    float64 fa, fb, fr;
+
+    fa = g_to_float64(env, GETPC(), a);
+    fb = g_to_float64(env, GETPC(), b);
+    fr = float64_add(fa, fb, &FP_STATUS);
+    return float64_to_g(fr);
+}
+
+uint64_t helper_subg(CPUAlphaState *env, uint64_t a, uint64_t b)
+{
+    float64 fa, fb, fr;
+
+    fa = g_to_float64(env, GETPC(), a);
+    fb = g_to_float64(env, GETPC(), b);
+    fr = float64_sub(fa, fb, &FP_STATUS);
+    return float64_to_g(fr);
+}
+
+uint64_t helper_mulg(CPUAlphaState *env, uint64_t a, uint64_t b)
+{
+    float64 fa, fb, fr;
+
+    fa = g_to_float64(env, GETPC(), a);
+    fb = g_to_float64(env, GETPC(), b);
+    fr = float64_mul(fa, fb, &FP_STATUS);
+    return float64_to_g(fr);
+}
+
+uint64_t helper_divg(CPUAlphaState *env, uint64_t a, uint64_t b)
+{
+    float64 fa, fb, fr;
+
+    fa = g_to_float64(env, GETPC(), a);
+    fb = g_to_float64(env, GETPC(), b);
+    fr = float64_div(fa, fb, &FP_STATUS);
+    return float64_to_g(fr);
+}
+
+uint64_t helper_sqrtg(CPUAlphaState *env, uint64_t a)
+{
+    float64 fa, fr;
+
+    fa = g_to_float64(env, GETPC(), a);
+    fr = float64_sqrt(fa, &FP_STATUS);
+    return float64_to_g(fr);
+}
+
+
+/* S floating (single) */
+
+/* Taken from linux/arch/alpha/kernel/traps.c, s_mem_to_reg.  */
+static inline uint64_t float32_to_s_int(uint32_t fi)
+{
+    uint32_t frac = fi & 0x7fffff;
+    uint32_t sign = fi >> 31;
+    uint32_t exp_msb = (fi >> 30) & 1;
+    uint32_t exp_low = (fi >> 23) & 0x7f;
+    uint32_t exp;
+
+    exp = (exp_msb << 10) | exp_low;
+    if (exp_msb) {
+        if (exp_low == 0x7f) {
+            exp = 0x7ff;
+        }
+    } else {
+        if (exp_low != 0x00) {
+            exp |= 0x380;
+        }
+    }
+
+    return (((uint64_t)sign << 63)
+            | ((uint64_t)exp << 52)
+            | ((uint64_t)frac << 29));
+}
+
+static inline uint64_t float32_to_s(float32 fa)
+{
+    CPU_FloatU a;
+    a.f = fa;
+    return float32_to_s_int(a.l);
+}
+
+static inline uint32_t s_to_float32_int(uint64_t a)
+{
+    return ((a >> 32) & 0xc0000000) | ((a >> 29) & 0x3fffffff);
+}
+
+static inline float32 s_to_float32(uint64_t a)
+{
+    CPU_FloatU r;
+    r.l = s_to_float32_int(a);
+    return r.f;
+}
+
+uint32_t helper_s_to_memory(uint64_t a)
+{
+    return s_to_float32_int(a);
+}
+
+uint64_t helper_memory_to_s(uint32_t a)
+{
+    return float32_to_s_int(a);
+}
+
+uint64_t helper_adds(CPUAlphaState *env, uint64_t a, uint64_t b)
+{
+    float32 fa, fb, fr;
+
+    fa = s_to_float32(a);
+    fb = s_to_float32(b);
+    fr = float32_add(fa, fb, &FP_STATUS);
+    return float32_to_s(fr);
+}
+
+uint64_t helper_subs(CPUAlphaState *env, uint64_t a, uint64_t b)
+{
+    float32 fa, fb, fr;
+
+    fa = s_to_float32(a);
+    fb = s_to_float32(b);
+    fr = float32_sub(fa, fb, &FP_STATUS);
+    return float32_to_s(fr);
+}
+
+uint64_t helper_muls(CPUAlphaState *env, uint64_t a, uint64_t b)
+{
+    float32 fa, fb, fr;
+
+    fa = s_to_float32(a);
+    fb = s_to_float32(b);
+    fr = float32_mul(fa, fb, &FP_STATUS);
+    return float32_to_s(fr);
+}
+
+uint64_t helper_divs(CPUAlphaState *env, uint64_t a, uint64_t b)
+{
+    float32 fa, fb, fr;
+
+    fa = s_to_float32(a);
+    fb = s_to_float32(b);
+    fr = float32_div(fa, fb, &FP_STATUS);
+    return float32_to_s(fr);
+}
+
+uint64_t helper_sqrts(CPUAlphaState *env, uint64_t a)
+{
+    float32 fa, fr;
+
+    fa = s_to_float32(a);
+    fr = float32_sqrt(fa, &FP_STATUS);
+    return float32_to_s(fr);
+}
+
+
+/* T floating (double) */
+static inline float64 t_to_float64(uint64_t a)
+{
+    /* Memory format is the same as float64 */
+    CPU_DoubleU r;
+    r.ll = a;
+    return r.d;
+}
+
+static inline uint64_t float64_to_t(float64 fa)
+{
+    /* Memory format is the same as float64 */
+    CPU_DoubleU r;
+    r.d = fa;
+    return r.ll;
+}
+
+uint64_t helper_addt(CPUAlphaState *env, uint64_t a, uint64_t b)
+{
+    float64 fa, fb, fr;
+
+    fa = t_to_float64(a);
+    fb = t_to_float64(b);
+    fr = float64_add(fa, fb, &FP_STATUS);
+    return float64_to_t(fr);
+}
+
+uint64_t helper_subt(CPUAlphaState *env, uint64_t a, uint64_t b)
+{
+    float64 fa, fb, fr;
+
+    fa = t_to_float64(a);
+    fb = t_to_float64(b);
+    fr = float64_sub(fa, fb, &FP_STATUS);
+    return float64_to_t(fr);
+}
+
+uint64_t helper_mult(CPUAlphaState *env, uint64_t a, uint64_t b)
+{
+    float64 fa, fb, fr;
+
+    fa = t_to_float64(a);
+    fb = t_to_float64(b);
+    fr = float64_mul(fa, fb, &FP_STATUS);
+    return float64_to_t(fr);
+}
+
+uint64_t helper_divt(CPUAlphaState *env, uint64_t a, uint64_t b)
+{
+    float64 fa, fb, fr;
+
+    fa = t_to_float64(a);
+    fb = t_to_float64(b);
+    fr = float64_div(fa, fb, &FP_STATUS);
+    return float64_to_t(fr);
+}
+
+uint64_t helper_sqrtt(CPUAlphaState *env, uint64_t a)
+{
+    float64 fa, fr;
+
+    fa = t_to_float64(a);
+    fr = float64_sqrt(fa, &FP_STATUS);
+    return float64_to_t(fr);
+}
+
+/* Comparisons */
+uint64_t helper_cmptun(CPUAlphaState *env, uint64_t a, uint64_t b)
+{
+    float64 fa, fb;
+
+    fa = t_to_float64(a);
+    fb = t_to_float64(b);
+
+    if (float64_unordered_quiet(fa, fb, &FP_STATUS)) {
+        return 0x4000000000000000ULL;
+    } else {
+        return 0;
+    }
+}
+
+uint64_t helper_cmpteq(CPUAlphaState *env, uint64_t a, uint64_t b)
+{
+    float64 fa, fb;
+
+    fa = t_to_float64(a);
+    fb = t_to_float64(b);
+
+    if (float64_eq_quiet(fa, fb, &FP_STATUS)) {
+        return 0x4000000000000000ULL;
+    } else {
+        return 0;
+    }
+}
+
+uint64_t helper_cmptle(CPUAlphaState *env, uint64_t a, uint64_t b)
+{
+    float64 fa, fb;
+
+    fa = t_to_float64(a);
+    fb = t_to_float64(b);
+
+    if (float64_le(fa, fb, &FP_STATUS)) {
+        return 0x4000000000000000ULL;
+    } else {
+        return 0;
+    }
+}
+
+uint64_t helper_cmptlt(CPUAlphaState *env, uint64_t a, uint64_t b)
+{
+    float64 fa, fb;
+
+    fa = t_to_float64(a);
+    fb = t_to_float64(b);
+
+    if (float64_lt(fa, fb, &FP_STATUS)) {
+        return 0x4000000000000000ULL;
+    } else {
+        return 0;
+    }
+}
+
+uint64_t helper_cmpgeq(CPUAlphaState *env, uint64_t a, uint64_t b)
+{
+    float64 fa, fb;
+
+    fa = g_to_float64(env, GETPC(), a);
+    fb = g_to_float64(env, GETPC(), b);
+
+    if (float64_eq_quiet(fa, fb, &FP_STATUS)) {
+        return 0x4000000000000000ULL;
+    } else {
+        return 0;
+    }
+}
+
+uint64_t helper_cmpgle(CPUAlphaState *env, uint64_t a, uint64_t b)
+{
+    float64 fa, fb;
+
+    fa = g_to_float64(env, GETPC(), a);
+    fb = g_to_float64(env, GETPC(), b);
+
+    if (float64_le(fa, fb, &FP_STATUS)) {
+        return 0x4000000000000000ULL;
+    } else {
+        return 0;
+    }
+}
+
+uint64_t helper_cmpglt(CPUAlphaState *env, uint64_t a, uint64_t b)
+{
+    float64 fa, fb;
+
+    fa = g_to_float64(env, GETPC(), a);
+    fb = g_to_float64(env, GETPC(), b);
+
+    if (float64_lt(fa, fb, &FP_STATUS)) {
+        return 0x4000000000000000ULL;
+    } else {
+        return 0;
+    }
+}
+
+/* Floating point format conversion */
+uint64_t helper_cvtts(CPUAlphaState *env, uint64_t a)
+{
+    float64 fa;
+    float32 fr;
+
+    fa = t_to_float64(a);
+    fr = float64_to_float32(fa, &FP_STATUS);
+    return float32_to_s(fr);
+}
+
+uint64_t helper_cvtst(CPUAlphaState *env, uint64_t a)
+{
+    float32 fa;
+    float64 fr;
+
+    fa = s_to_float32(a);
+    fr = float32_to_float64(fa, &FP_STATUS);
+    return float64_to_t(fr);
+}
+
+uint64_t helper_cvtqs(CPUAlphaState *env, uint64_t a)
+{
+    float32 fr = int64_to_float32(a, &FP_STATUS);
+    return float32_to_s(fr);
+}
+
+/* Implement float64 to uint64 conversion without saturation -- we must
+   supply the truncated result.  This behaviour is used by the compiler
+   to get unsigned conversion for free with the same instruction.
+
+   The VI flag is set when overflow or inexact exceptions should be raised.  */
+
+static inline uint64_t inline_cvttq(CPUAlphaState *env, uint64_t a,
+                                    int roundmode, int VI)
+{
+    uint64_t frac, ret = 0;
+    uint32_t exp, sign, exc = 0;
+    int shift;
+
+    sign = (a >> 63);
+    exp = (uint32_t)(a >> 52) & 0x7ff;
+    frac = a & 0xfffffffffffffull;
+
+    if (exp == 0) {
+        if (unlikely(frac != 0)) {
+            goto do_underflow;
+        }
+    } else if (exp == 0x7ff) {
+        exc = (frac ? float_flag_invalid : VI ? float_flag_overflow : 0);
+    } else {
+        /* Restore implicit bit.  */
+        frac |= 0x10000000000000ull;
+
+        shift = exp - 1023 - 52;
+        if (shift >= 0) {
+            /* In this case the number is so large that we must shift
+               the fraction left.  There is no rounding to do.  */
+            if (shift < 63) {
+                ret = frac << shift;
+                if (VI && (ret >> shift) != frac) {
+                    exc = float_flag_overflow;
+                }
+            }
+        } else {
+            uint64_t round;
+
+            /* In this case the number is smaller than the fraction as
+               represented by the 52 bit number.  Here we must think
+               about rounding the result.  Handle this by shifting the
+               fractional part of the number into the high bits of ROUND.
+               This will let us efficiently handle round-to-nearest.  */
+            shift = -shift;
+            if (shift < 63) {
+                ret = frac >> shift;
+                round = frac << (64 - shift);
+            } else {
+                /* The exponent is so small we shift out everything.
+                   Leave a sticky bit for proper rounding below.  */
+            do_underflow:
+                round = 1;
+            }
+
+            if (round) {
+                exc = (VI ? float_flag_inexact : 0);
+                switch (roundmode) {
+                case float_round_nearest_even:
+                    if (round == (1ull << 63)) {
+                        /* Fraction is exactly 0.5; round to even.  */
+                        ret += (ret & 1);
+                    } else if (round > (1ull << 63)) {
+                        ret += 1;
+                    }
+                    break;
+                case float_round_to_zero:
+                    break;
+                case float_round_up:
+                    ret += 1 - sign;
+                    break;
+                case float_round_down:
+                    ret += sign;
+                    break;
+                }
+            }
+        }
+        if (sign) {
+            ret = -ret;
+        }
+    }
+    if (unlikely(exc)) {
+        float_raise(exc, &FP_STATUS);
+    }
+
+    return ret;
+}
+
+uint64_t helper_cvttq(CPUAlphaState *env, uint64_t a)
+{
+    return inline_cvttq(env, a, FP_STATUS.float_rounding_mode, 1);
+}
+
+uint64_t helper_cvttq_c(CPUAlphaState *env, uint64_t a)
+{
+    return inline_cvttq(env, a, float_round_to_zero, 0);
+}
+
+uint64_t helper_cvttq_svic(CPUAlphaState *env, uint64_t a)
+{
+    return inline_cvttq(env, a, float_round_to_zero, 1);
+}
+
+uint64_t helper_cvtqt(CPUAlphaState *env, uint64_t a)
+{
+    float64 fr = int64_to_float64(a, &FP_STATUS);
+    return float64_to_t(fr);
+}
+
+uint64_t helper_cvtqf(CPUAlphaState *env, uint64_t a)
+{
+    float32 fr = int64_to_float32(a, &FP_STATUS);
+    return float32_to_f(fr);
+}
+
+uint64_t helper_cvtgf(CPUAlphaState *env, uint64_t a)
+{
+    float64 fa;
+    float32 fr;
+
+    fa = g_to_float64(env, GETPC(), a);
+    fr = float64_to_float32(fa, &FP_STATUS);
+    return float32_to_f(fr);
+}
+
+uint64_t helper_cvtgq(CPUAlphaState *env, uint64_t a)
+{
+    float64 fa = g_to_float64(env, GETPC(), a);
+    return float64_to_int64_round_to_zero(fa, &FP_STATUS);
+}
+
+uint64_t helper_cvtqg(CPUAlphaState *env, uint64_t a)
+{
+    float64 fr;
+    fr = int64_to_float64(a, &FP_STATUS);
+    return float64_to_g(fr);
+}