From: Richard Henderson <richard.henderson@linaro.org>
To: qemu-devel@nongnu.org
Cc: "Philippe Mathieu-Daudé" <philmd@linaro.org>
Subject: [PULL 07/11] target/alpha: Use float64_to_int64_modulo for CVTTQ
Date: Sat, 1 Jul 2023 08:55:06 +0200 [thread overview]
Message-ID: <20230701065510.514743-8-richard.henderson@linaro.org> (raw)
In-Reply-To: <20230701065510.514743-1-richard.henderson@linaro.org>
For the most part we can use the new generic routine,
though exceptions need some post-processing to sort
invalid from integer overflow.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20230527141910.1885950-4-richard.henderson@linaro.org>
---
target/alpha/fpu_helper.c | 85 +++++++++------------------------------
1 file changed, 18 insertions(+), 67 deletions(-)
diff --git a/target/alpha/fpu_helper.c b/target/alpha/fpu_helper.c
index 3ff8bb456d..63d9e9ce39 100644
--- a/target/alpha/fpu_helper.c
+++ b/target/alpha/fpu_helper.c
@@ -453,78 +453,29 @@ uint64_t helper_cvtqs(CPUAlphaState *env, uint64_t a)
static uint64_t do_cvttq(CPUAlphaState *env, uint64_t a, int roundmode)
{
- uint64_t frac, ret = 0;
- uint32_t exp, sign, exc = 0;
- int shift;
+ float64 fa;
+ int64_t ret;
+ uint32_t exc;
- sign = (a >> 63);
- exp = (uint32_t)(a >> 52) & 0x7ff;
- frac = a & 0xfffffffffffffull;
+ fa = t_to_float64(a);
+ ret = float64_to_int64_modulo(fa, roundmode, &FP_STATUS);
- if (exp == 0) {
- if (unlikely(frac != 0) && !env->fp_status.flush_inputs_to_zero) {
- goto do_underflow;
- }
- } else if (exp == 0x7ff) {
- exc = FPCR_INV;
- } else {
- /* Restore implicit bit. */
- frac |= 0x10000000000000ull;
+ exc = get_float_exception_flags(&FP_STATUS);
+ if (unlikely(exc)) {
+ set_float_exception_flags(0, &FP_STATUS);
- 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 < 64) {
- ret = frac << shift;
- }
- /* Check for overflow. Note the special case of -0x1p63. */
- if (shift >= 11 && a != 0xC3E0000000000000ull) {
+ /* We need to massage the resulting exceptions. */
+ if (exc & float_flag_invalid_cvti) {
+ /* Overflow, either normal or infinity. */
+ if (float64_is_infinity(fa)) {
+ exc = FPCR_INV;
+ } else {
exc = FPCR_IOV | FPCR_INE;
}
- } 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 = FPCR_INE;
- 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;
+ } else if (exc & float_flag_invalid) {
+ exc = FPCR_INV;
+ } else if (exc & float_flag_inexact) {
+ exc = FPCR_INE;
}
}
env->error_code = exc;
--
2.34.1
next prev parent reply other threads:[~2023-07-01 6:57 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-01 6:54 [PULL 00/11] tcg and misc patch queue Richard Henderson
2023-07-01 6:55 ` [PULL 01/11] ui/dbus: fix build errors in dbus_update_gl_cb and dbus_call_update_gl Richard Henderson
2023-07-01 6:55 ` [PULL 02/11] audio: dbus requires pixman Richard Henderson
2023-07-01 6:55 ` [PULL 03/11] accel/tcg: Fix start page passed to tb_invalidate_phys_page_range__locked Richard Henderson
2023-07-01 6:55 ` [PULL 04/11] accel/tcg: Assert one page in tb_invalidate_phys_page_range__locked Richard Henderson
2023-07-01 6:55 ` [PULL 05/11] fpu: Add float64_to_int{32,64}_modulo Richard Henderson
2023-07-01 6:55 ` [PULL 06/11] tests/tcg/alpha: Add test for cvttq Richard Henderson
2023-07-01 6:55 ` Richard Henderson [this message]
2023-07-01 6:55 ` [PULL 08/11] target/arm: Use float64_to_int32_modulo for FJCVTZS Richard Henderson
2023-07-01 6:55 ` [PULL 09/11] tcg: Reduce tcg_assert_listed_vecop() scope Richard Henderson
2023-07-01 6:55 ` [PULL 10/11] target/nios2 : Explicitly ask for target-endian loads and stores Richard Henderson
2023-07-01 6:55 ` [PULL 11/11] linux-user: Avoid mmap of the last byte of the reserved_va Richard Henderson
2023-07-01 8:10 ` [PULL 00/11] tcg and misc patch queue Philippe Mathieu-Daudé
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