qfloat16: re-merge the F16C content into qfloat16.cpp

The bugs we had noticed previously are believed to be fixed. MSVC will
do per-function updating of AVX content where necessary and the ICC
issue is no longer relevant.

Change-Id: I2bbf422288924c198645fffd16a9235f2d73cc19
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>

2 files changed, 29 insertions, 101 deletions

diff --git a/src/corelib/global/qfloat16.cpp b/src/corelib/global/qfloat16.cpp
index 9ef197b3a1..834d82e0ea 100644
--- a/src/corelib/global/qfloat16.cpp
+++ b/src/corelib/global/qfloat16.cpp
@@ -197,17 +197,36 @@ static inline bool hasFastF16()
     return qCpuHasFeature(F16C) && qCpuHasFeature(AVX);
 }
 
-extern "C" {
-#ifdef QFLOAT16_INCLUDE_FAST
-#  define f16cextern    static
-#else
-#  define f16cextern    extern
-#endif
-
-f16cextern void qFloatToFloat16_fast(quint16 *out, const float *in, qsizetype len) noexcept;
-f16cextern void qFloatFromFloat16_fast(float *out, const quint16 *in, qsizetype len) noexcept;
+QT_FUNCTION_TARGET(F16C)
+void qFloatToFloat16_fast(quint16 *out, const float *in, qsizetype len) Q_DECL_NOEXCEPT
+{
+    qsizetype i = 0;
+    int epilog_i;
+    for (; i < len - 7; i += 8)
+        _mm_storeu_si128((__m128i *)(out + i), _mm256_cvtps_ph(_mm256_loadu_ps(in + i), 0));
+    if (i < len - 3) {
+        _mm_storel_epi64((__m128i *)(out + i), _mm_cvtps_ph(_mm_loadu_ps(in + i), 0));
+        i += 4;
+    }
+    // Inlining "qfloat16::qfloat16(float f)":
+    for (epilog_i = 0; i < len && epilog_i < 3; ++i, ++epilog_i)
+        out[i] = _mm_extract_epi16(_mm_cvtps_ph(_mm_set_ss(in[i]), 0), 0);
+}
 
-#undef f16cextern
+QT_FUNCTION_TARGET(F16C)
+void qFloatFromFloat16_fast(float *out, const quint16 *in, qsizetype len) Q_DECL_NOEXCEPT
+{
+    qsizetype i = 0;
+    int epilog_i;
+    for (; i < len - 7; i += 8)
+        _mm256_storeu_ps(out + i, _mm256_cvtph_ps(_mm_loadu_si128((const __m128i *)(in + i))));
+    if (i < len - 3) {
+        _mm_storeu_ps(out + i, _mm_cvtph_ps(_mm_loadl_epi64((const __m128i *)(in + i))));
+        i += 4;
+    }
+    // Inlining "qfloat16::operator float()":
+    for (epilog_i = 0; i < len && epilog_i < 3; ++i, ++epilog_i)
+        out[i] = _mm_cvtss_f32(_mm_cvtph_ps(_mm_cvtsi32_si128(in[i])));
 }
 
 #elif defined(__ARM_FP16_FORMAT_IEEE) && defined(__ARM_NEON__) && (__ARM_FP & 2)
@@ -292,6 +311,3 @@ Q_CORE_EXPORT void qFloatFromFloat16(float *out, const qfloat16 *in, qsizetype l
 QT_END_NAMESPACE
 
 #include "qfloat16tables.cpp"
-#ifdef QFLOAT16_INCLUDE_FAST
-#  include "qfloat16_f16c.c"
-#endif
diff --git a/src/corelib/global/qfloat16_f16c.c b/src/corelib/global/qfloat16_f16c.c
deleted file mode 100644
index d60a021bdb..0000000000
--- a/src/corelib/global/qfloat16_f16c.c
+++ /dev/null
@@ -1,88 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2017 The Qt Company Ltd.
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the QtCore module of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 3 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL3 included in the
-** packaging of this file. Please review the following information to
-** ensure the GNU Lesser General Public License version 3 requirements
-** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 2.0 or (at your option) the GNU General
-** Public license version 3 or any later version approved by the KDE Free
-** Qt Foundation. The licenses are as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-2.0.html and
-** https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-#include "private/qsimd_p.h"
-
-// The x86 F16C instructions operate on AVX registers, so AVX support is
-// required.
-#if QT_COMPILER_SUPPORTS_HERE(AVX)
-
-#ifdef __cplusplus
-QT_BEGIN_NAMESPACE
-extern "C" {
-#endif
-
-QT_FUNCTION_TARGET(F16C)
-void qFloatToFloat16_fast(quint16 *out, const float *in, qsizetype len) Q_DECL_NOEXCEPT
-{
-    qsizetype i = 0;
-    int epilog_i;
-    for (; i < len - 7; i += 8)
-        _mm_storeu_si128((__m128i *)(out + i), _mm256_cvtps_ph(_mm256_loadu_ps(in + i), 0));
-    if (i < len - 3) {
-        _mm_storel_epi64((__m128i *)(out + i), _mm_cvtps_ph(_mm_loadu_ps(in + i), 0));
-        i += 4;
-    }
-    // Inlining "qfloat16::qfloat16(float f)":
-    for (epilog_i = 0; i < len && epilog_i < 3; ++i, ++epilog_i)
-        out[i] = _mm_extract_epi16(_mm_cvtps_ph(_mm_set_ss(in[i]), 0), 0);
-}
-
-QT_FUNCTION_TARGET(F16C)
-void qFloatFromFloat16_fast(float *out, const quint16 *in, qsizetype len) Q_DECL_NOEXCEPT
-{
-    qsizetype i = 0;
-    int epilog_i;
-    for (; i < len - 7; i += 8)
-        _mm256_storeu_ps(out + i, _mm256_cvtph_ps(_mm_loadu_si128((const __m128i *)(in + i))));
-    if (i < len - 3) {
-        _mm_storeu_ps(out + i, _mm_cvtph_ps(_mm_loadl_epi64((const __m128i *)(in + i))));
-        i += 4;
-    }
-    // Inlining "qfloat16::operator float()":
-    for (epilog_i = 0; i < len && epilog_i < 3; ++i, ++epilog_i)
-        out[i] = _mm_cvtss_f32(_mm_cvtph_ps(_mm_cvtsi32_si128(in[i])));
-}
-
-#ifdef __cplusplus
-} // extern "C"
-QT_END_NAMESPACE
-#endif
-
-#endif // QT_COMPILER_SUPPORTS_HERE(AVX)