[PATCH] softfloat: Mark base int-to-float routines QEMU_FLATTEN

[PATCH] softfloat: Mark base int-to-float routines QEMU_FLATTEN

[Richard Henderson]

This merges the int_to_float routine and the round_pack_canonical
routine into the same function, allowing the FloatParts structure
to be decomposed by the compiler.

This results in a 60-75% speedup of the flattened function.

Leave the narrower integer inputs to tail-call the int64_t version.

Buglink: https://bugs.launchpad.net/qemu/+bug/1892081
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 fpu/softfloat.c | 24 ++++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)

diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index 7b6aee9323..2cbcf5bf10 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -2794,7 +2794,8 @@ static FloatParts int_to_float(int64_t a, int scale, float_status *status)
     return r;
 }
 
-float16 int64_to_float16_scalbn(int64_t a, int scale, float_status *status)
+float16 QEMU_FLATTEN
+int64_to_float16_scalbn(int64_t a, int scale, float_status *status)
 {
     FloatParts pa = int_to_float(a, scale, status);
     return float16_round_pack_canonical(pa, status);
@@ -2830,7 +2831,8 @@ float16 int8_to_float16(int8_t a, float_status *status)
     return int64_to_float16_scalbn(a, 0, status);
 }
 
-float32 int64_to_float32_scalbn(int64_t a, int scale, float_status *status)
+float32 QEMU_FLATTEN
+int64_to_float32_scalbn(int64_t a, int scale, float_status *status)
 {
     FloatParts pa = int_to_float(a, scale, status);
     return float32_round_pack_canonical(pa, status);
@@ -2861,7 +2863,8 @@ float32 int16_to_float32(int16_t a, float_status *status)
     return int64_to_float32_scalbn(a, 0, status);
 }
 
-float64 int64_to_float64_scalbn(int64_t a, int scale, float_status *status)
+float64 QEMU_FLATTEN
+int64_to_float64_scalbn(int64_t a, int scale, float_status *status)
 {
     FloatParts pa = int_to_float(a, scale, status);
     return float64_round_pack_canonical(pa, status);
@@ -2897,7 +2900,8 @@ float64 int16_to_float64(int16_t a, float_status *status)
  * to the bfloat16 format.
  */
 
-bfloat16 int64_to_bfloat16_scalbn(int64_t a, int scale, float_status *status)
+bfloat16 QEMU_FLATTEN
+int64_to_bfloat16_scalbn(int64_t a, int scale, float_status *status)
 {
     FloatParts pa = int_to_float(a, scale, status);
     return bfloat16_round_pack_canonical(pa, status);
@@ -2959,7 +2963,8 @@ static FloatParts uint_to_float(uint64_t a, int scale, float_status *status)
     return r;
 }
 
-float16 uint64_to_float16_scalbn(uint64_t a, int scale, float_status *status)
+float16 QEMU_FLATTEN
+uint64_to_float16_scalbn(uint64_t a, int scale, float_status *status)
 {
     FloatParts pa = uint_to_float(a, scale, status);
     return float16_round_pack_canonical(pa, status);
@@ -2995,7 +3000,8 @@ float16 uint8_to_float16(uint8_t a, float_status *status)
     return uint64_to_float16_scalbn(a, 0, status);
 }
 
-float32 uint64_to_float32_scalbn(uint64_t a, int scale, float_status *status)
+float32 QEMU_FLATTEN
+uint64_to_float32_scalbn(uint64_t a, int scale, float_status *status)
 {
     FloatParts pa = uint_to_float(a, scale, status);
     return float32_round_pack_canonical(pa, status);
@@ -3026,7 +3032,8 @@ float32 uint16_to_float32(uint16_t a, float_status *status)
     return uint64_to_float32_scalbn(a, 0, status);
 }
 
-float64 uint64_to_float64_scalbn(uint64_t a, int scale, float_status *status)
+float64 QEMU_FLATTEN
+uint64_to_float64_scalbn(uint64_t a, int scale, float_status *status)
 {
     FloatParts pa = uint_to_float(a, scale, status);
     return float64_round_pack_canonical(pa, status);
@@ -3062,7 +3069,8 @@ float64 uint16_to_float64(uint16_t a, float_status *status)
  * bfloat16 format.
  */
 
-bfloat16 uint64_to_bfloat16_scalbn(uint64_t a, int scale, float_status *status)
+bfloat16 QEMU_FLATTEN
+uint64_to_bfloat16_scalbn(uint64_t a, int scale, float_status *status)
 {
     FloatParts pa = uint_to_float(a, scale, status);
     return bfloat16_round_pack_canonical(pa, status);
-- 
2.25.1

Re: [PATCH] softfloat: Mark base int-to-float routines QEMU_FLATTEN

[no-reply]

Patchew URL: https://patchew.org/QEMU/20201018203334.1229243-1-richard.henderson@linaro.org/



Hi,

This series seems to have some coding style problems. See output below for
more information:

Type: series
Message-id: 20201018203334.1229243-1-richard.henderson@linaro.org
Subject: [PATCH] softfloat: Mark base int-to-float routines QEMU_FLATTEN

=== TEST SCRIPT BEGIN ===
#!/bin/bash
git rev-parse base > /dev/null || exit 0
git config --local diff.renamelimit 0
git config --local diff.renames True
git config --local diff.algorithm histogram
./scripts/checkpatch.pl --mailback base..
=== TEST SCRIPT END ===

Updating 3c8cf5a9c21ff8782164d1def7f44bd888713384
Switched to a new branch 'test'
4ffd616 softfloat: Mark base int-to-float routines QEMU_FLATTEN

=== OUTPUT BEGIN ===
ERROR: spaces required around that '*' (ctx:WxV)
#29: FILE: fpu/softfloat.c:2779:
+int64_to_float16_scalbn(int64_t a, int scale, float_status *status)
                                                            ^

ERROR: spaces required around that '*' (ctx:WxV)
#39: FILE: fpu/softfloat.c:2816:
+int64_to_float32_scalbn(int64_t a, int scale, float_status *status)
                                                            ^

ERROR: spaces required around that '*' (ctx:WxV)
#49: FILE: fpu/softfloat.c:2848:
+int64_to_float64_scalbn(int64_t a, int scale, float_status *status)
                                                            ^

ERROR: spaces required around that '*' (ctx:WxV)
#59: FILE: fpu/softfloat.c:2885:
+int64_to_bfloat16_scalbn(int64_t a, int scale, float_status *status)
                                                             ^

ERROR: spaces required around that '*' (ctx:WxV)
#69: FILE: fpu/softfloat.c:2948:
+uint64_to_float16_scalbn(uint64_t a, int scale, float_status *status)
                                                              ^

ERROR: spaces required around that '*' (ctx:WxV)
#79: FILE: fpu/softfloat.c:2985:
+uint64_to_float32_scalbn(uint64_t a, int scale, float_status *status)
                                                              ^

ERROR: spaces required around that '*' (ctx:WxV)
#89: FILE: fpu/softfloat.c:3017:
+uint64_to_float64_scalbn(uint64_t a, int scale, float_status *status)
                                                              ^

ERROR: spaces required around that '*' (ctx:WxV)
#99: FILE: fpu/softfloat.c:3054:
+uint64_to_bfloat16_scalbn(uint64_t a, int scale, float_status *status)
                                                               ^

total: 8 errors, 0 warnings, 72 lines checked

Commit 4ffd616f4c5d (softfloat: Mark base int-to-float routines QEMU_FLATTEN) has style problems, please review.  If any of these errors
are false positives report them to the maintainer, see
CHECKPATCH in MAINTAINERS.
=== OUTPUT END ===

Test command exited with code: 1


The full log is available at
http://patchew.org/logs/20201018203334.1229243-1-richard.henderson@linaro.org/testing.checkpatch/?type=message.
---
Email generated automatically by Patchew [https://patchew.org/].
Please send your feedback to patchew-devel@redhat.com

Re: [PATCH] softfloat: Mark base int-to-float routines QEMU_FLATTEN

[Philippe Mathieu-Daudé]

On 10/18/20 10:33 PM, Richard Henderson wrote:
> This merges the int_to_float routine and the round_pack_canonical
> routine into the same function, allowing the FloatParts structure
> to be decomposed by the compiler.
> 
> This results in a 60-75% speedup of the flattened function.
> 
> Leave the narrower integer inputs to tail-call the int64_t version.
> 

Reported-by: Ahmed Karaman <ahmedkrmn@outlook.com>

> Buglink: https://bugs.launchpad.net/qemu/+bug/1892081
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

> ---
>   fpu/softfloat.c | 24 ++++++++++++++++--------
>   1 file changed, 16 insertions(+), 8 deletions(-)
> 
> diff --git a/fpu/softfloat.c b/fpu/softfloat.c
> index 7b6aee9323..2cbcf5bf10 100644
> --- a/fpu/softfloat.c
> +++ b/fpu/softfloat.c
> @@ -2794,7 +2794,8 @@ static FloatParts int_to_float(int64_t a, int scale, float_status *status)
>       return r;
>   }
>   
> -float16 int64_to_float16_scalbn(int64_t a, int scale, float_status *status)
> +float16 QEMU_FLATTEN
> +int64_to_float16_scalbn(int64_t a, int scale, float_status *status)
>   {
>       FloatParts pa = int_to_float(a, scale, status);
>       return float16_round_pack_canonical(pa, status);
> @@ -2830,7 +2831,8 @@ float16 int8_to_float16(int8_t a, float_status *status)
>       return int64_to_float16_scalbn(a, 0, status);
>   }
>   
> -float32 int64_to_float32_scalbn(int64_t a, int scale, float_status *status)
> +float32 QEMU_FLATTEN
> +int64_to_float32_scalbn(int64_t a, int scale, float_status *status)
>   {
>       FloatParts pa = int_to_float(a, scale, status);
>       return float32_round_pack_canonical(pa, status);
> @@ -2861,7 +2863,8 @@ float32 int16_to_float32(int16_t a, float_status *status)
>       return int64_to_float32_scalbn(a, 0, status);
>   }
>   
> -float64 int64_to_float64_scalbn(int64_t a, int scale, float_status *status)
> +float64 QEMU_FLATTEN
> +int64_to_float64_scalbn(int64_t a, int scale, float_status *status)
>   {
>       FloatParts pa = int_to_float(a, scale, status);
>       return float64_round_pack_canonical(pa, status);
> @@ -2897,7 +2900,8 @@ float64 int16_to_float64(int16_t a, float_status *status)
>    * to the bfloat16 format.
>    */
>   
> -bfloat16 int64_to_bfloat16_scalbn(int64_t a, int scale, float_status *status)
> +bfloat16 QEMU_FLATTEN
> +int64_to_bfloat16_scalbn(int64_t a, int scale, float_status *status)
>   {
>       FloatParts pa = int_to_float(a, scale, status);
>       return bfloat16_round_pack_canonical(pa, status);
> @@ -2959,7 +2963,8 @@ static FloatParts uint_to_float(uint64_t a, int scale, float_status *status)
>       return r;
>   }
>   
> -float16 uint64_to_float16_scalbn(uint64_t a, int scale, float_status *status)
> +float16 QEMU_FLATTEN
> +uint64_to_float16_scalbn(uint64_t a, int scale, float_status *status)
>   {
>       FloatParts pa = uint_to_float(a, scale, status);
>       return float16_round_pack_canonical(pa, status);
> @@ -2995,7 +3000,8 @@ float16 uint8_to_float16(uint8_t a, float_status *status)
>       return uint64_to_float16_scalbn(a, 0, status);
>   }
>   
> -float32 uint64_to_float32_scalbn(uint64_t a, int scale, float_status *status)
> +float32 QEMU_FLATTEN
> +uint64_to_float32_scalbn(uint64_t a, int scale, float_status *status)
>   {
>       FloatParts pa = uint_to_float(a, scale, status);
>       return float32_round_pack_canonical(pa, status);
> @@ -3026,7 +3032,8 @@ float32 uint16_to_float32(uint16_t a, float_status *status)
>       return uint64_to_float32_scalbn(a, 0, status);
>   }
>   
> -float64 uint64_to_float64_scalbn(uint64_t a, int scale, float_status *status)
> +float64 QEMU_FLATTEN
> +uint64_to_float64_scalbn(uint64_t a, int scale, float_status *status)
>   {
>       FloatParts pa = uint_to_float(a, scale, status);
>       return float64_round_pack_canonical(pa, status);
> @@ -3062,7 +3069,8 @@ float64 uint16_to_float64(uint16_t a, float_status *status)
>    * bfloat16 format.
>    */
>   
> -bfloat16 uint64_to_bfloat16_scalbn(uint64_t a, int scale, float_status *status)
> +bfloat16 QEMU_FLATTEN
> +uint64_to_bfloat16_scalbn(uint64_t a, int scale, float_status *status)
>   {
>       FloatParts pa = uint_to_float(a, scale, status);
>       return bfloat16_round_pack_canonical(pa, status);
> 

Re: [PATCH] softfloat: Mark base int-to-float routines QEMU_FLATTEN

[Alex Bennée]

Richard Henderson <richard.henderson@linaro.org> writes:

> This merges the int_to_float routine and the round_pack_canonical
> routine into the same function, allowing the FloatParts structure
> to be decomposed by the compiler.
>
> This results in a 60-75% speedup of the flattened function.
>
> Leave the narrower integer inputs to tail-call the int64_t version.
>
> Buglink: https://bugs.launchpad.net/qemu/+bug/1892081
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

-- 
Alex Bennée