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softfloat: Use post test for floatN_mul

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The existing f{32,64}_addsub_post test, which checks for zero
inputs, is identical to f{32,64}_mul_fast_test.  Which means
we can eliminate the fast_test/fast_op hooks in favor of
reusing the same post hook.

This means we have one fewer test along the fast path for multiply.

Tested-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson 2020-05-04 16:57:21 -07:00
parent f2465433b4
commit b240c9c497
1 changed files with 14 additions and 51 deletions
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65
fpu/softfloat.c
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@ -339,12 +339,10 @@ static inline bool f64_is_inf(union_float64 a)
return float64_is_infinity(a.s);
}
/* Note: @fast_test and @post can be NULL */
static inline float32
float32_gen2(float32 xa, float32 xb, float_status *s,
hard_f32_op2_fn hard, soft_f32_op2_fn soft,
f32_check_fn pre, f32_check_fn post,
f32_check_fn fast_test, soft_f32_op2_fn fast_op)
f32_check_fn pre, f32_check_fn post)
{
union_float32 ua, ub, ur;
@ -359,17 +357,12 @@ float32_gen2(float32 xa, float32 xb, float_status *s,
if (unlikely(!pre(ua, ub))) {
goto soft;
}
if (fast_test && fast_test(ua, ub)) {
return fast_op(ua.s, ub.s, s);
}
ur.h = hard(ua.h, ub.h);
if (unlikely(f32_is_inf(ur))) {
s->float_exception_flags |= float_flag_overflow;
} else if (unlikely(fabsf(ur.h) <= FLT_MIN)) {
if (post == NULL || post(ua, ub)) {
goto soft;
}
} else if (unlikely(fabsf(ur.h) <= FLT_MIN) && post(ua, ub)) {
goto soft;
}
return ur.s;
@ -380,8 +373,7 @@ float32_gen2(float32 xa, float32 xb, float_status *s,
static inline float64
float64_gen2(float64 xa, float64 xb, float_status *s,
hard_f64_op2_fn hard, soft_f64_op2_fn soft,
f64_check_fn pre, f64_check_fn post,
f64_check_fn fast_test, soft_f64_op2_fn fast_op)
f64_check_fn pre, f64_check_fn post)
{
union_float64 ua, ub, ur;
@ -396,17 +388,12 @@ float64_gen2(float64 xa, float64 xb, float_status *s,
if (unlikely(!pre(ua, ub))) {
goto soft;
}
if (fast_test && fast_test(ua, ub)) {
return fast_op(ua.s, ub.s, s);
}
ur.h = hard(ua.h, ub.h);
if (unlikely(f64_is_inf(ur))) {
s->float_exception_flags |= float_flag_overflow;
} else if (unlikely(fabs(ur.h) <= DBL_MIN)) {
if (post == NULL || post(ua, ub)) {
goto soft;
}
} else if (unlikely(fabs(ur.h) <= DBL_MIN) && post(ua, ub)) {
goto soft;
}
return ur.s;
@ -1115,7 +1102,7 @@ static double hard_f64_sub(double a, double b)
return a - b;
}
static bool f32_addsub_post(union_float32 a, union_float32 b)
static bool f32_addsubmul_post(union_float32 a, union_float32 b)
{
if (QEMU_HARDFLOAT_2F32_USE_FP) {
return !(fpclassify(a.h) == FP_ZERO && fpclassify(b.h) == FP_ZERO);
@ -1123,7 +1110,7 @@ static bool f32_addsub_post(union_float32 a, union_float32 b)
return !(float32_is_zero(a.s) && float32_is_zero(b.s));
}
static bool f64_addsub_post(union_float64 a, union_float64 b)
static bool f64_addsubmul_post(union_float64 a, union_float64 b)
{
if (QEMU_HARDFLOAT_2F64_USE_FP) {
return !(fpclassify(a.h) == FP_ZERO && fpclassify(b.h) == FP_ZERO);
@ -1136,14 +1123,14 @@ static float32 float32_addsub(float32 a, float32 b, float_status *s,
hard_f32_op2_fn hard, soft_f32_op2_fn soft)
{
return float32_gen2(a, b, s, hard, soft,
f32_is_zon2, f32_addsub_post, NULL, NULL);
f32_is_zon2, f32_addsubmul_post);
}
static float64 float64_addsub(float64 a, float64 b, float_status *s,
hard_f64_op2_fn hard, soft_f64_op2_fn soft)
{
return float64_gen2(a, b, s, hard, soft,
f64_is_zon2, f64_addsub_post, NULL, NULL);
f64_is_zon2, f64_addsubmul_post);
}
float32 QEMU_FLATTEN
@ -1258,42 +1245,18 @@ static double hard_f64_mul(double a, double b)
return a * b;
}
static bool f32_mul_fast_test(union_float32 a, union_float32 b)
{
return float32_is_zero(a.s) || float32_is_zero(b.s);
}
static bool f64_mul_fast_test(union_float64 a, union_float64 b)
{
return float64_is_zero(a.s) || float64_is_zero(b.s);
}
static float32 f32_mul_fast_op(float32 a, float32 b, float_status *s)
{
bool signbit = float32_is_neg(a) ^ float32_is_neg(b);
return float32_set_sign(float32_zero, signbit);
}
static float64 f64_mul_fast_op(float64 a, float64 b, float_status *s)
{
bool signbit = float64_is_neg(a) ^ float64_is_neg(b);
return float64_set_sign(float64_zero, signbit);
}
float32 QEMU_FLATTEN
float32_mul(float32 a, float32 b, float_status *s)
{
return float32_gen2(a, b, s, hard_f32_mul, soft_f32_mul,
f32_is_zon2, NULL, f32_mul_fast_test, f32_mul_fast_op);
f32_is_zon2, f32_addsubmul_post);
}
float64 QEMU_FLATTEN
float64_mul(float64 a, float64 b, float_status *s)
{
return float64_gen2(a, b, s, hard_f64_mul, soft_f64_mul,
f64_is_zon2, NULL, f64_mul_fast_test, f64_mul_fast_op);
f64_is_zon2, f64_addsubmul_post);
}
/*
@ -1834,14 +1797,14 @@ float32 QEMU_FLATTEN
float32_div(float32 a, float32 b, float_status *s)
{
return float32_gen2(a, b, s, hard_f32_div, soft_f32_div,
f32_div_pre, f32_div_post, NULL, NULL);
f32_div_pre, f32_div_post);
}
float64 QEMU_FLATTEN
float64_div(float64 a, float64 b, float_status *s)
{
return float64_gen2(a, b, s, hard_f64_div, soft_f64_div,
f64_div_pre, f64_div_post, NULL, NULL);
f64_div_pre, f64_div_post);
}
/*