From d1ff996788a41280e2e0213b9571afeca4d6ca90 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Tue, 5 Nov 2024 10:09:53 +0000 Subject: target/arm: Explicitly set 2-NaN propagation rule Set the 2-NaN propagation rule explicitly in the float_status words we use. We wrap this plus the pre-existing setting of the tininess-before-rounding flag in a new function arm_set_default_fp_behaviours() to avoid repetition, since we have a lot of float_status words at this point. The situation with FPA11 emulation in linux-user is a little odd, and arguably "correct" behaviour there would be to exactly match a real Linux kernel's FPA11 emulation. However FPA11 emulation is essentially dead at this point and so it seems better to continue with QEMU's current behaviour and leave a comment describing the situation. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 20241025141254.2141506-4-peter.maydell@linaro.org --- fpu/softfloat-specialize.c.inc | 13 ++----------- 1 file changed, 2 insertions(+), 11 deletions(-) (limited to 'fpu') diff --git a/fpu/softfloat-specialize.c.inc b/fpu/softfloat-specialize.c.inc index fae6794a15..70cd3628b5 100644 --- a/fpu/softfloat-specialize.c.inc +++ b/fpu/softfloat-specialize.c.inc @@ -402,19 +402,10 @@ static int pickNaN(FloatClass a_cls, FloatClass b_cls, /* target didn't set the rule: fall back to old ifdef choices */ #if defined(TARGET_AVR) || defined(TARGET_HEXAGON) \ || defined(TARGET_RISCV) || defined(TARGET_SH4) \ - || defined(TARGET_TRICORE) + || defined(TARGET_TRICORE) || defined(TARGET_ARM) g_assert_not_reached(); -#elif defined(TARGET_ARM) || defined(TARGET_MIPS) || defined(TARGET_HPPA) || \ +#elif defined(TARGET_MIPS) || defined(TARGET_HPPA) || \ defined(TARGET_LOONGARCH64) || defined(TARGET_S390X) - /* - * ARM mandated NaN propagation rules (see FPProcessNaNs()), take - * the first of: - * 1. A if it is signaling - * 2. B if it is signaling - * 3. A (quiet) - * 4. B (quiet) - * A signaling NaN is always quietened before returning it. - */ /* * According to MIPS specifications, if one of the two operands is * a sNaN, a new qNaN has to be generated. This is done in -- cgit v1.2.3