diff options
| author | Peter Maydell <peter.maydell@linaro.org> | 2024-12-11 15:31:05 +0000 |
|---|---|---|
| committer | Peter Maydell <peter.maydell@linaro.org> | 2024-12-11 15:31:05 +0000 |
| commit | 29fbe4786ecc1613224e64e188c93067ced6e750 (patch) | |
| tree | 0ba73889dc5b7f44ea12ff0ebb9beeb770d34ba1 | |
| parent | 369cb9cfe033b43a07e13265598c3df195ce2e4e (diff) | |
| download | qemu-29fbe4786ecc1613224e64e188c93067ced6e750.zip qemu-29fbe4786ecc1613224e64e188c93067ced6e750.tar.gz qemu-29fbe4786ecc1613224e64e188c93067ced6e750.tar.bz2 | |
target/arm: Set default NaN pattern explicitly
Set the default NaN pattern explicitly for the arm target.
This includes setting it for the old linux-user nwfpe emulation.
For nwfpe, our default doesn't match the real kernel, but we
avoid making a behaviour change in this commit.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20241202131347.498124-41-peter.maydell@linaro.org
| -rw-r--r-- | linux-user/arm/nwfpe/fpa11.c | 5 | ||||
| -rw-r--r-- | target/arm/cpu.c | 2 |
2 files changed, 7 insertions, 0 deletions
diff --git a/linux-user/arm/nwfpe/fpa11.c b/linux-user/arm/nwfpe/fpa11.c index 8356beb..0f1afbd 100644 --- a/linux-user/arm/nwfpe/fpa11.c +++ b/linux-user/arm/nwfpe/fpa11.c @@ -69,6 +69,11 @@ void resetFPA11(void) * this late date. */ set_float_2nan_prop_rule(float_2nan_prop_s_ab, &fpa11->fp_status); + /* + * Use the same default NaN value as Arm VFP. This doesn't match + * the Linux kernel's nwfpe emulation, which uses an all-1s value. + */ + set_float_default_nan_pattern(0b01000000, &fpa11->fp_status); } void SetRoundingMode(const unsigned int opcode) diff --git a/target/arm/cpu.c b/target/arm/cpu.c index c81f6df..4f7e18e 100644 --- a/target/arm/cpu.c +++ b/target/arm/cpu.c @@ -179,6 +179,7 @@ void arm_register_el_change_hook(ARMCPU *cpu, ARMELChangeHookFn *hook, * the pseudocode function the arguments are in the order c, a, b. * * 0 * Inf + NaN returns the default NaN if the input NaN is quiet, * and the input NaN if it is signalling + * * Default NaN has sign bit clear, msb frac bit set */ static void arm_set_default_fp_behaviours(float_status *s) { @@ -186,6 +187,7 @@ static void arm_set_default_fp_behaviours(float_status *s) set_float_2nan_prop_rule(float_2nan_prop_s_ab, s); set_float_3nan_prop_rule(float_3nan_prop_s_cab, s); set_float_infzeronan_rule(float_infzeronan_dnan_if_qnan, s); + set_float_default_nan_pattern(0b01000000, s); } static void cp_reg_reset(gpointer key, gpointer value, gpointer opaque) |