[RFC PATCH 2/8] softfloat: Use int128.h for some operations
From: Richard Henderson
Use our Int128, which wraps the compiler's __int128_t,
instead of open-coding left shifts and arithmetic.
We'd need to extend Int128 to have unsigned operations
to replace more than these three.
Reviewed-by: David Hildenbrand
Signed-off-by: Richard Henderson
Signed-off-by: Alex Bennée
Message-Id: <20200925152047.709901-3-richard.hender...@linaro.org>
---
include/fpu/softfloat-macros.h | 39 +-
1 file changed, 20 insertions(+), 19 deletions(-)
diff --git a/include/fpu/softfloat-macros.h b/include/fpu/softfloat-macros.h
index 57845f8af0..95d88d05b8 100644
--- a/include/fpu/softfloat-macros.h
+++ b/include/fpu/softfloat-macros.h
@@ -84,6 +84,7 @@ this code that are retained.
#include "fpu/softfloat-types.h"
#include "qemu/host-utils.h"
+#include "qemu/int128.h"
/*
| Shifts `a' right by the number of bits given in `count'. If any nonzero
@@ -352,13 +353,11 @@ static inline void shortShift128Left(uint64_t a0,
uint64_t a1, int count,
static inline void shift128Left(uint64_t a0, uint64_t a1, int count,
uint64_t *z0Ptr, uint64_t *z1Ptr)
{
-if (count < 64) {
-*z1Ptr = a1 << count;
-*z0Ptr = count == 0 ? a0 : (a0 << count) | (a1 >> (-count & 63));
-} else {
-*z1Ptr = 0;
-*z0Ptr = a1 << (count - 64);
-}
+Int128 a = int128_make128(a1, a0);
+Int128 z = int128_lshift(a, count);
+
+*z0Ptr = int128_gethi(z);
+*z1Ptr = int128_getlo(z);
}
/*
@@ -405,15 +404,15 @@ static inline void
**/
static inline void
- add128(
- uint64_t a0, uint64_t a1, uint64_t b0, uint64_t b1, uint64_t *z0Ptr,
uint64_t *z1Ptr )
+add128(uint64_t a0, uint64_t a1, uint64_t b0, uint64_t b1,
+ uint64_t *z0Ptr, uint64_t *z1Ptr)
{
-uint64_t z1;
-
-z1 = a1 + b1;
-*z1Ptr = z1;
-*z0Ptr = a0 + b0 + ( z1 < a1 );
+Int128 a = int128_make128(a1, a0);
+Int128 b = int128_make128(b1, b0);
+Int128 z = int128_add(a, b);
+*z0Ptr = int128_gethi(z);
+*z1Ptr = int128_getlo(z);
}
/*
@@ -463,13 +462,15 @@ static inline void
**/
static inline void
- sub128(
- uint64_t a0, uint64_t a1, uint64_t b0, uint64_t b1, uint64_t *z0Ptr,
uint64_t *z1Ptr )
+sub128(uint64_t a0, uint64_t a1, uint64_t b0, uint64_t b1,
+ uint64_t *z0Ptr, uint64_t *z1Ptr)
{
+Int128 a = int128_make128(a1, a0);
+Int128 b = int128_make128(b1, b0);
+Int128 z = int128_sub(a, b);
-*z1Ptr = a1 - b1;
-*z0Ptr = a0 - b0 - ( a1 < b1 );
-
+*z0Ptr = int128_gethi(z);
+*z1Ptr = int128_getlo(z);
}
/*
--
2.20.1
Re: [PATCH 2/8] softfloat: Use int128.h for some operations
On 24.09.20 03:24, Richard Henderson wrote:
> Use our Int128, which wraps the compiler's __int128_t,
> instead of open-coding left shifts and arithmetic.
> We'd need to extend Int128 to have unsigned operations
> to replace more than these three.
>
> Signed-off-by: Richard Henderson
> ---
> include/fpu/softfloat-macros.h | 39 +-
> 1 file changed, 20 insertions(+), 19 deletions(-)
>
> diff --git a/include/fpu/softfloat-macros.h b/include/fpu/softfloat-macros.h
> index 57845f8af0..95d88d05b8 100644
> --- a/include/fpu/softfloat-macros.h
> +++ b/include/fpu/softfloat-macros.h
> @@ -84,6 +84,7 @@ this code that are retained.
>
> #include "fpu/softfloat-types.h"
> #include "qemu/host-utils.h"
> +#include "qemu/int128.h"
>
>
> /*
> | Shifts `a' right by the number of bits given in `count'. If any nonzero
> @@ -352,13 +353,11 @@ static inline void shortShift128Left(uint64_t a0,
> uint64_t a1, int count,
> static inline void shift128Left(uint64_t a0, uint64_t a1, int count,
> uint64_t *z0Ptr, uint64_t *z1Ptr)
> {
> -if (count < 64) {
> -*z1Ptr = a1 << count;
> -*z0Ptr = count == 0 ? a0 : (a0 << count) | (a1 >> (-count & 63));
> -} else {
> -*z1Ptr = 0;
> -*z0Ptr = a1 << (count - 64);
> -}
> +Int128 a = int128_make128(a1, a0);
> +Int128 z = int128_lshift(a, count);
> +
> +*z0Ptr = int128_gethi(z);
> +*z1Ptr = int128_getlo(z);
> }
>
>
> /*
> @@ -405,15 +404,15 @@ static inline void
>
> **/
>
> static inline void
> - add128(
> - uint64_t a0, uint64_t a1, uint64_t b0, uint64_t b1, uint64_t *z0Ptr,
> uint64_t *z1Ptr )
> +add128(uint64_t a0, uint64_t a1, uint64_t b0, uint64_t b1,
> + uint64_t *z0Ptr, uint64_t *z1Ptr)
> {
> -uint64_t z1;
> -
> -z1 = a1 + b1;
> -*z1Ptr = z1;
> -*z0Ptr = a0 + b0 + ( z1 < a1 );
> +Int128 a = int128_make128(a1, a0);
> +Int128 b = int128_make128(b1, b0);
> +Int128 z = int128_add(a, b);
>
> +*z0Ptr = int128_gethi(z);
> +*z1Ptr = int128_getlo(z);
> }
>
>
> /*
> @@ -463,13 +462,15 @@ static inline void
>
> **/
>
> static inline void
> - sub128(
> - uint64_t a0, uint64_t a1, uint64_t b0, uint64_t b1, uint64_t *z0Ptr,
> uint64_t *z1Ptr )
> +sub128(uint64_t a0, uint64_t a1, uint64_t b0, uint64_t b1,
> + uint64_t *z0Ptr, uint64_t *z1Ptr)
> {
> +Int128 a = int128_make128(a1, a0);
> +Int128 b = int128_make128(b1, b0);
> +Int128 z = int128_sub(a, b);
>
> -*z1Ptr = a1 - b1;
> -*z0Ptr = a0 - b0 - ( a1 < b1 );
> -
> +*z0Ptr = int128_gethi(z);
> +*z1Ptr = int128_getlo(z);
> }
>
>
> /*
>
Reviewed-by: David Hildenbrand
--
Thanks,
David / dhildenb
[PATCH 2/8] softfloat: Use int128.h for some operations
Use our Int128, which wraps the compiler's __int128_t,
instead of open-coding left shifts and arithmetic.
We'd need to extend Int128 to have unsigned operations
to replace more than these three.
Signed-off-by: Richard Henderson
---
include/fpu/softfloat-macros.h | 39 +-
1 file changed, 20 insertions(+), 19 deletions(-)
diff --git a/include/fpu/softfloat-macros.h b/include/fpu/softfloat-macros.h
index 57845f8af0..95d88d05b8 100644
--- a/include/fpu/softfloat-macros.h
+++ b/include/fpu/softfloat-macros.h
@@ -84,6 +84,7 @@ this code that are retained.
#include "fpu/softfloat-types.h"
#include "qemu/host-utils.h"
+#include "qemu/int128.h"
/*
| Shifts `a' right by the number of bits given in `count'. If any nonzero
@@ -352,13 +353,11 @@ static inline void shortShift128Left(uint64_t a0,
uint64_t a1, int count,
static inline void shift128Left(uint64_t a0, uint64_t a1, int count,
uint64_t *z0Ptr, uint64_t *z1Ptr)
{
-if (count < 64) {
-*z1Ptr = a1 << count;
-*z0Ptr = count == 0 ? a0 : (a0 << count) | (a1 >> (-count & 63));
-} else {
-*z1Ptr = 0;
-*z0Ptr = a1 << (count - 64);
-}
+Int128 a = int128_make128(a1, a0);
+Int128 z = int128_lshift(a, count);
+
+*z0Ptr = int128_gethi(z);
+*z1Ptr = int128_getlo(z);
}
/*
@@ -405,15 +404,15 @@ static inline void
**/
static inline void
- add128(
- uint64_t a0, uint64_t a1, uint64_t b0, uint64_t b1, uint64_t *z0Ptr,
uint64_t *z1Ptr )
+add128(uint64_t a0, uint64_t a1, uint64_t b0, uint64_t b1,
+ uint64_t *z0Ptr, uint64_t *z1Ptr)
{
-uint64_t z1;
-
-z1 = a1 + b1;
-*z1Ptr = z1;
-*z0Ptr = a0 + b0 + ( z1 < a1 );
+Int128 a = int128_make128(a1, a0);
+Int128 b = int128_make128(b1, b0);
+Int128 z = int128_add(a, b);
+*z0Ptr = int128_gethi(z);
+*z1Ptr = int128_getlo(z);
}
/*
@@ -463,13 +462,15 @@ static inline void
**/
static inline void
- sub128(
- uint64_t a0, uint64_t a1, uint64_t b0, uint64_t b1, uint64_t *z0Ptr,
uint64_t *z1Ptr )
+sub128(uint64_t a0, uint64_t a1, uint64_t b0, uint64_t b1,
+ uint64_t *z0Ptr, uint64_t *z1Ptr)
{
+Int128 a = int128_make128(a1, a0);
+Int128 b = int128_make128(b1, b0);
+Int128 z = int128_sub(a, b);
-*z1Ptr = a1 - b1;
-*z0Ptr = a0 - b0 - ( a1 < b1 );
-
+*z0Ptr = int128_gethi(z);
+*z1Ptr = int128_getlo(z);
}
/*
--
2.25.1
