From: Max Chou <[email protected]> ARM Alt HP raises different exceptions on overflow than is standard for IEEE when saturating a value. Add a flag to control this effect.
Signed-off-by: Max Chou <[email protected]> [rth: Split out of a larger patch] Signed-off-by: Richard Henderson <[email protected]> --- fpu/softfloat.c | 6 +++++- fpu/softfloat-parts.c.inc | 4 +++- 2 files changed, 8 insertions(+), 2 deletions(-) diff --git a/fpu/softfloat.c b/fpu/softfloat.c index 18098c4cdd..209eb59b48 100644 --- a/fpu/softfloat.c +++ b/fpu/softfloat.c @@ -542,7 +542,9 @@ typedef enum __attribute__((__packed__)) { * The following optional modifiers are available: * exp_max_kind: affects how exp == exp_max is interpreted * has_explicit_bit: has an explicit integer bit; this affects whether - * the float_status floatx80_behaviour handling applies + * the float_status floatx80_behaviour handling applies + * overflow_raises_invalid: for float_expmax_normal, raise invalid + * instead of overflow. */ typedef struct { int exp_size; @@ -553,6 +555,7 @@ typedef struct { int frac_shift; FloatFmtExpMaxKind exp_max_kind; bool has_explicit_bit; + bool overflow_raises_invalid; uint64_t round_mask; } FloatFmt; @@ -576,6 +579,7 @@ static const FloatFmt float16_params = { static const FloatFmt float16_params_ahp = { FLOAT_PARAMS(5, 10), .exp_max_kind = float_expmax_normal, + .overflow_raises_invalid = true, }; static const FloatFmt bfloat16_params = { diff --git a/fpu/softfloat-parts.c.inc b/fpu/softfloat-parts.c.inc index d3c9c7a913..eada83f7a4 100644 --- a/fpu/softfloat-parts.c.inc +++ b/fpu/softfloat-parts.c.inc @@ -348,7 +348,9 @@ static void partsN(uncanon_normal)(FloatPartsN *p, float_status *s, case float_expmax_normal: if (unlikely(exp > exp_max)) { /* Overflow. Return the maximum normal. */ - flags = float_flag_invalid; + flags = (fmt->overflow_raises_invalid + ? float_flag_invalid + : float_flag_overflow | float_flag_inexact); exp = exp_max; frac_allones(p); p->frac_lo &= ~round_mask; -- 2.43.0
