[compiler-rt] r209781 - Refactor extendsfdf2.
Joerg Sonnenberger
joerg at bec.de
Wed May 28 17:54:26 PDT 2014
Author: joerg
Date: Wed May 28 19:54:26 2014
New Revision: 209781
URL: http://llvm.org/viewvc/llvm-project?rev=209781&view=rev
Log:
Refactor extendsfdf2.
Patch by: GuanHong Liu
Differential Revision: http://reviews.llvm.org/D3887
Added:
compiler-rt/trunk/lib/builtins/fp_extend.h
compiler-rt/trunk/lib/builtins/fp_extend_impl.inc
Modified:
compiler-rt/trunk/lib/builtins/extendsfdf2.c
Modified: compiler-rt/trunk/lib/builtins/extendsfdf2.c
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/builtins/extendsfdf2.c?rev=209781&r1=209780&r2=209781&view=diff
==============================================================================
--- compiler-rt/trunk/lib/builtins/extendsfdf2.c (original)
+++ compiler-rt/trunk/lib/builtins/extendsfdf2.c Wed May 28 19:54:26 2014
@@ -7,132 +7,13 @@
//
//===----------------------------------------------------------------------===//
//
-// This file implements a fairly generic conversion from a narrower to a wider
-// IEEE-754 floating-point type. The constants and types defined following the
-// includes below parameterize the conversion.
-//
-// This routine can be trivially adapted to support conversions from
-// half-precision or to quad-precision. It does not support types that don't
-// use the usual IEEE-754 interchange formats; specifically, some work would be
-// needed to adapt it to (for example) the Intel 80-bit format or PowerPC
-// double-double format.
-//
-// Note please, however, that this implementation is only intended to support
-// *widening* operations; if you need to convert to a *narrower* floating-point
-// type (e.g. double -> float), then this routine will not do what you want it
-// to.
-//
-// It also requires that integer types at least as large as both formats
-// are available on the target platform; this may pose a problem when trying
-// to add support for quad on some 32-bit systems, for example. You also may
-// run into trouble finding an appropriate CLZ function for wide source types;
-// you will likely need to roll your own on some platforms.
-//
-// Finally, the following assumptions are made:
-//
-// 1. floating-point types and integer types have the same endianness on the
-// target platform
-//
-// 2. quiet NaNs, if supported, are indicated by the leading bit of the
-// significand field being set
-//
-//===----------------------------------------------------------------------===//
-
-#include "int_lib.h"
-typedef float src_t;
-typedef uint32_t src_rep_t;
-#define SRC_REP_C UINT32_C
-static const int srcSigBits = 23;
-#define src_rep_t_clz __builtin_clz
-
-typedef double dst_t;
-typedef uint64_t dst_rep_t;
-#define DST_REP_C UINT64_C
-static const int dstSigBits = 52;
-
-// End of specialization parameters. Two helper routines for conversion to and
-// from the representation of floating-point data as integer values follow.
-
-static inline src_rep_t srcToRep(src_t x) {
- const union { src_t f; src_rep_t i; } rep = {.f = x};
- return rep.i;
-}
-
-static inline dst_t dstFromRep(dst_rep_t x) {
- const union { dst_t f; dst_rep_t i; } rep = {.i = x};
- return rep.f;
-}
-
-// End helper routines. Conversion implementation follows.
+#define SRC_SINGLE
+#define DST_DOUBLE
+#include "fp_extend_impl.inc"
ARM_EABI_FNALIAS(f2d, extendsfdf2)
-COMPILER_RT_ABI dst_t
-__extendsfdf2(src_t a) {
-
- // Various constants whose values follow from the type parameters.
- // Any reasonable optimizer will fold and propagate all of these.
- const int srcBits = sizeof(src_t)*CHAR_BIT;
- const int srcExpBits = srcBits - srcSigBits - 1;
- const int srcInfExp = (1 << srcExpBits) - 1;
- const int srcExpBias = srcInfExp >> 1;
-
- const src_rep_t srcMinNormal = SRC_REP_C(1) << srcSigBits;
- const src_rep_t srcInfinity = (src_rep_t)srcInfExp << srcSigBits;
- const src_rep_t srcSignMask = SRC_REP_C(1) << (srcSigBits + srcExpBits);
- const src_rep_t srcAbsMask = srcSignMask - 1;
- const src_rep_t srcQNaN = SRC_REP_C(1) << (srcSigBits - 1);
- const src_rep_t srcNaNCode = srcQNaN - 1;
-
- const int dstBits = sizeof(dst_t)*CHAR_BIT;
- const int dstExpBits = dstBits - dstSigBits - 1;
- const int dstInfExp = (1 << dstExpBits) - 1;
- const int dstExpBias = dstInfExp >> 1;
-
- const dst_rep_t dstMinNormal = DST_REP_C(1) << dstSigBits;
-
- // Break a into a sign and representation of the absolute value
- const src_rep_t aRep = srcToRep(a);
- const src_rep_t aAbs = aRep & srcAbsMask;
- const src_rep_t sign = aRep & srcSignMask;
- dst_rep_t absResult;
-
- if (aAbs - srcMinNormal < srcInfinity - srcMinNormal) {
- // a is a normal number.
- // Extend to the destination type by shifting the significand and
- // exponent into the proper position and rebiasing the exponent.
- absResult = (dst_rep_t)aAbs << (dstSigBits - srcSigBits);
- absResult += (dst_rep_t)(dstExpBias - srcExpBias) << dstSigBits;
- }
-
- else if (aAbs >= srcInfinity) {
- // a is NaN or infinity.
- // Conjure the result by beginning with infinity, then setting the qNaN
- // bit (if needed) and right-aligning the rest of the trailing NaN
- // payload field.
- absResult = (dst_rep_t)dstInfExp << dstSigBits;
- absResult |= (dst_rep_t)(aAbs & srcQNaN) << (dstSigBits - srcSigBits);
- absResult |= aAbs & srcNaNCode;
- }
-
- else if (aAbs) {
- // a is denormal.
- // renormalize the significand and clear the leading bit, then insert
- // the correct adjusted exponent in the destination type.
- const int scale = src_rep_t_clz(aAbs) - src_rep_t_clz(srcMinNormal);
- absResult = (dst_rep_t)aAbs << (dstSigBits - srcSigBits + scale);
- absResult ^= dstMinNormal;
- const int resultExponent = dstExpBias - srcExpBias - scale + 1;
- absResult |= (dst_rep_t)resultExponent << dstSigBits;
- }
-
- else {
- // a is zero.
- absResult = 0;
- }
-
- // Apply the signbit to (dst_t)abs(a).
- const dst_rep_t result = absResult | (dst_rep_t)sign << (dstBits - srcBits);
- return dstFromRep(result);
+COMPILER_RT_ABI double __extendsfdf2(float a) {
+ return __extendXfYf2__(a);
}
Added: compiler-rt/trunk/lib/builtins/fp_extend.h
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/builtins/fp_extend.h?rev=209781&view=auto
==============================================================================
--- compiler-rt/trunk/lib/builtins/fp_extend.h (added)
+++ compiler-rt/trunk/lib/builtins/fp_extend.h Wed May 28 19:54:26 2014
@@ -0,0 +1,76 @@
+//===-lib/fp_extend.h - low precision -> high precision conversion -*- C -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Set source and destination setting
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef FP_EXTEND_HEADER
+#define FP_EXTEND_HEADER
+
+#include "int_lib.h"
+
+#if defined SRC_SINGLE
+typedef float src_t;
+typedef uint32_t src_rep_t;
+#define SRC_REP_C UINT32_C
+static const int srcSigBits = 23;
+#define src_rep_t_clz __builtin_clz
+
+#elif defined SRC_DOUBLE
+typedef double src_t;
+typedef uint64_t src_rep_t;
+#define SRC_REP_C UINT64_C
+static const int srcSigBits = 52;
+static inline int src_rep_t_clz(src_rep_t a) {
+#if defined __LP64__
+ return __builtin_clzl(a);
+#else
+ if (a & REP_C(0xffffffff00000000))
+ return __builtin_clz(a >> 32);
+ else
+ return 32 + __builtin_clz(a & REP_C(0xffffffff));
+#endif
+}
+
+#else
+#error Source should be single precision or double precision!
+#endif //end source precision
+
+#if defined DST_DOUBLE
+typedef double dst_t;
+typedef uint64_t dst_rep_t;
+#define DST_REP_C UINT64_C
+static const int dstSigBits = 52;
+
+#elif defined DST_QUAD
+typedef long double dst_t;
+typedef __uint128_t dst_rep_t;
+#define DST_REP_C (__uint128_t)
+static const int dstSigBits = 112;
+
+#else
+#error Destination should be double precision or quad precision!
+#endif //end destination precision
+
+// End of specialization parameters. Two helper routines for conversion to and
+// from the representation of floating-point data as integer values follow.
+
+static inline src_rep_t srcToRep(src_t x) {
+ const union { src_t f; src_rep_t i; } rep = {.f = x};
+ return rep.i;
+}
+
+static inline dst_t dstFromRep(dst_rep_t x) {
+ const union { dst_t f; dst_rep_t i; } rep = {.i = x};
+ return rep.f;
+}
+// End helper routines. Conversion implementation follows.
+
+#endif //FP_EXTEND_HEADER
Added: compiler-rt/trunk/lib/builtins/fp_extend_impl.inc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/builtins/fp_extend_impl.inc?rev=209781&view=auto
==============================================================================
--- compiler-rt/trunk/lib/builtins/fp_extend_impl.inc (added)
+++ compiler-rt/trunk/lib/builtins/fp_extend_impl.inc Wed May 28 19:54:26 2014
@@ -0,0 +1,106 @@
+//=-lib/fp_extend_impl.inc - low precision -> high precision conversion -*-- -//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements a fairly generic conversion from a narrower to a wider
+// IEEE-754 floating-point type. The constants and types defined following the
+// includes below parameterize the conversion.
+//
+// It does not support types that don't use the usual IEEE-754 interchange
+// formats; specifically, some work would be needed to adapt it to
+// (for example) the Intel 80-bit format or PowerPC double-double format.
+//
+// Note please, however, that this implementation is only intended to support
+// *widening* operations; if you need to convert to a *narrower* floating-point
+// type (e.g. double -> float), then this routine will not do what you want it
+// to.
+//
+// It also requires that integer types at least as large as both formats
+// are available on the target platform; this may pose a problem when trying
+// to add support for quad on some 32-bit systems, for example. You also may
+// run into trouble finding an appropriate CLZ function for wide source types;
+// you will likely need to roll your own on some platforms.
+//
+// Finally, the following assumptions are made:
+//
+// 1. floating-point types and integer types have the same endianness on the
+// target platform
+//
+// 2. quiet NaNs, if supported, are indicated by the leading bit of the
+// significand field being set
+//
+//===----------------------------------------------------------------------===//
+
+#include "fp_extend.h"
+
+static inline dst_t __extendXfYf2__(src_t a) {
+ // Various constants whose values follow from the type parameters.
+ // Any reasonable optimizer will fold and propagate all of these.
+ const int srcBits = sizeof(src_t)*CHAR_BIT;
+ const int srcExpBits = srcBits - srcSigBits - 1;
+ const int srcInfExp = (1 << srcExpBits) - 1;
+ const int srcExpBias = srcInfExp >> 1;
+
+ const src_rep_t srcMinNormal = SRC_REP_C(1) << srcSigBits;
+ const src_rep_t srcInfinity = (src_rep_t)srcInfExp << srcSigBits;
+ const src_rep_t srcSignMask = SRC_REP_C(1) << (srcSigBits + srcExpBits);
+ const src_rep_t srcAbsMask = srcSignMask - 1;
+ const src_rep_t srcQNaN = SRC_REP_C(1) << (srcSigBits - 1);
+ const src_rep_t srcNaNCode = srcQNaN - 1;
+
+ const int dstBits = sizeof(dst_t)*CHAR_BIT;
+ const int dstExpBits = dstBits - dstSigBits - 1;
+ const int dstInfExp = (1 << dstExpBits) - 1;
+ const int dstExpBias = dstInfExp >> 1;
+
+ const dst_rep_t dstMinNormal = DST_REP_C(1) << dstSigBits;
+
+ // Break a into a sign and representation of the absolute value
+ const src_rep_t aRep = srcToRep(a);
+ const src_rep_t aAbs = aRep & srcAbsMask;
+ const src_rep_t sign = aRep & srcSignMask;
+ dst_rep_t absResult;
+
+ if (aAbs - srcMinNormal < srcInfinity - srcMinNormal) {
+ // a is a normal number.
+ // Extend to the destination type by shifting the significand and
+ // exponent into the proper position and rebiasing the exponent.
+ absResult = (dst_rep_t)aAbs << (dstSigBits - srcSigBits);
+ absResult += (dst_rep_t)(dstExpBias - srcExpBias) << dstSigBits;
+ }
+
+ else if (aAbs >= srcInfinity) {
+ // a is NaN or infinity.
+ // Conjure the result by beginning with infinity, then setting the qNaN
+ // bit (if needed) and right-aligning the rest of the trailing NaN
+ // payload field.
+ absResult = (dst_rep_t)dstInfExp << dstSigBits;
+ absResult |= (dst_rep_t)(aAbs & srcQNaN) << (dstSigBits - srcSigBits);
+ absResult |= (dst_rep_t)(aAbs & srcNaNCode) << (dstSigBits - srcSigBits);
+ }
+
+ else if (aAbs) {
+ // a is denormal.
+ // renormalize the significand and clear the leading bit, then insert
+ // the correct adjusted exponent in the destination type.
+ const int scale = src_rep_t_clz(aAbs) - src_rep_t_clz(srcMinNormal);
+ absResult = (dst_rep_t)aAbs << (dstSigBits - srcSigBits + scale);
+ absResult ^= dstMinNormal;
+ const int resultExponent = dstExpBias - srcExpBias - scale + 1;
+ absResult |= (dst_rep_t)resultExponent << dstSigBits;
+ }
+
+ else {
+ // a is zero.
+ absResult = 0;
+ }
+
+ // Apply the signbit to (dst_t)abs(a).
+ const dst_rep_t result = absResult | (dst_rep_t)sign << (dstBits - srcBits);
+ return dstFromRep(result);
+}
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