[libc] Add differential and performance targets for sqrtf

[hedingarcia]

Summary

Comparing the runtime of the sqrt functions from LLVM libc with the system libc:

function	perf - LLVM libc	perf - MSVCRT
sqrtf - Windows	44.05 sec (44051715500 ns)	417.84 sec (417843359900 ns) = 6.96 mins

function	perf - LLVM libc	perf - glibc
sqrtf - Linux	30.48 sec (30479458632 ns)	43.72 sec (43716901527 ns)

By running the differential test:

function	diff
sqrtf - Windows	0 differing results
sqrtf - Linux	0 differing results

[sivachandra]

Do you have any results to share?

[hedingarcia]

Yes, comparing the runtime of the sqrt functions from LLVM libc with the system libc:

function	perf - LLVM libc	perf - MSVCRT
sqrtf - Windows	44.05 sec (44051715500 ns)	417.84 sec (417843359900 ns) = 6.96 mins

function	perf - LLVM libc	perf - glibc
sqrtf - Linux	30.48 sec (30479458632 ns)	43.72 sec (43716901527 ns)

And by running the differential test:

function	diff
sqrtf - Windows	0 differing results
sqrtf - Linux	0 differing results

[sivachandra]

Thanks a lot for sharing.

[aeubanks]

putting the stats in the description would be nice

libc/test/src/math/differential_testing/sqrtf_diff.cpp

2–3

these are messed up, should be one line

libc/test/src/math/differential_testing/sqrtf_perf.cpp

2–3

ditto

[hedingarcia]

[libc] Fixed comments format

libc/test/src/math/differential_testing/CMakeLists.txt

add_diff_binary(
   SRCS
     expm1f_perf.cpp
   DEPENDS
     .single_input_single_output_diff
     libc.src.math.expm1f
   COMPILE_OPTIONS
     -fno-builtin
 )
+
+add_diff_binary(
+  sqrtf_diff
+  SRCS
+    sqrtf_diff.cpp
+  DEPENDS
+    .single_input_single_output_diff
+    libc.src.math.sqrtf
+)
+
+add_diff_binary(
+  sqrtf_perf
+  SRCS
+    sqrtf_perf.cpp
+  DEPENDS
+    .single_input_single_output_diff
+    libc.src.math.sqrtf
+  COMPILE_OPTIONS
+    -fno-builtin
+)

libc/test/src/math/differential_testing/sqrtf_diff.cpp

+//===-- Differential test for sqrtf
+//----------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "SingleInputSingleOutputDiff.h"
+
+#include "src/math/sqrtf.h"
+
+#include <math.h>
+
+SINGLE_INPUT_SINGLE_OUTPUT_DIFF(float, __llvm_libc::sqrtf, ::sqrtf,
+                                "sqrtf_diff.log")

libc/test/src/math/differential_testing/sqrtf_perf.cpp

+//===-- Differential test for sqrtf
+//----------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "SingleInputSingleOutputDiff.h"
+
+#include "src/math/sqrtf.h"
+
+#include <math.h>
+
+SINGLE_INPUT_SINGLE_OUTPUT_PERF(float, __llvm_libc::sqrtf, ::sqrtf,
+                                "sqrtf_perf.log")