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authorJakub Jelinek <jakub@redhat.com>2007-07-12 18:26:36 +0000
committerJakub Jelinek <jakub@redhat.com>2007-07-12 18:26:36 +0000
commit0ecb606cb6cf65de1d9fc8a919bceb4be476c602 (patch)
tree2ea1f8305970753e4a657acb2ccc15ca3eec8e2c /sysdeps/ia64/fpu/s_round.S
parent7d58530341304d403a6626d7f7a1913165fe2f32 (diff)
downloadglibc-0ecb606cb6cf65de1d9fc8a919bceb4be476c602.tar.gz
2.5-18.1
Diffstat (limited to 'sysdeps/ia64/fpu/s_round.S')
-rw-r--r--sysdeps/ia64/fpu/s_round.S322
1 files changed, 153 insertions, 169 deletions
diff --git a/sysdeps/ia64/fpu/s_round.S b/sysdeps/ia64/fpu/s_round.S
index b08ede1740..ed5ffae205 100644
--- a/sysdeps/ia64/fpu/s_round.S
+++ b/sysdeps/ia64/fpu/s_round.S
@@ -1,11 +1,10 @@
.file "round.s"
-// Copyright (C) 2000, 2001, Intel Corporation
+
+// Copyright (c) 2000 - 2003, Intel Corporation
// All rights reserved.
-//
-// Contributed 10/25/2000 by John Harrison, Cristina Iordache, Ted Kubaska,
-// Bob Norin, Tom Rowan, Shane Story, and Ping Tak Peter Tang of the
-// Computational Software Lab, Intel Corporation.
+//
+// Contributed 2000 by the Intel Numerics Group, Intel Corporation
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
@@ -21,229 +20,214 @@
// * The name of Intel Corporation may not be used to endorse or promote
// products derived from this software without specific prior written
// permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL INTEL OR ITS
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL INTEL OR ITS
// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
-// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
-// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
-// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
// OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY OR TORT (INCLUDING
-// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
-// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-//
+// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
// Intel Corporation is the author of this code, and requests that all
-// problem reports or change requests be submitted to it directly at
-// http://developer.intel.com/opensource.
+// problem reports or change requests be submitted to it directly at
+// http://www.intel.com/software/products/opensource/libraries/num.htm.
//
// History
//==============================================================
-// 10/25/2000: Created
+// 10/25/00 Initial version
+// 06/14/01 Changed cmp to an equivalent form
+// 05/20/02 Cleaned up namespace and sf0 syntax
+// 01/20/03 Improved performance and reduced code size
+// 04/18/03 Eliminate possible WAW dependency warning
+// 09/03/03 Improved performance
//==============================================================
-//
+
// API
//==============================================================
// double round(double x)
-//
+//==============================================================
-#include "libm_support.h"
+// general input registers:
+// r14 - r18
-// general input registers:
-//
-round_GR_half = r14
-round_GR_big = r15
-round_GR_expmask = r16
-round_GR_signexp = r17
-round_GR_exp = r18
-round_GR_expdiff = r19
-
-// predicate registers used:
-// p6 - p10
+rSignexp = r14
+rExp = r15
+rExpMask = r16
+rBigexp = r17
+rExpHalf = r18
-// floating-point registers used:
+// floating-point registers:
+// f8 - f13
-ROUND_NORM_f8 = f9
-ROUND_TRUNC_f8 = f10
-ROUND_RINT_f8 = f11
-ROUND_FLOAT_TRUNC_f8 = f12
-ROUND_FLOAT_RINT_f8 = f13
-ROUND_REMAINDER = f14
-ROUND_HALF = f15
+fXtruncInt = f9
+fNormX = f10
+fHalf = f11
+fInc = f12
+fRem = f13
+
+// predicate registers used:
+// p6 - p10
// Overview of operation
//==============================================================
-
// double round(double x)
-// Return an integer value (represented as a double) that is x
-// rounded to nearest integer, halfway cases rounded away from
-// zero.
+// Return an integer value (represented as a double) that is x
+// rounded to nearest integer, halfway cases rounded away from
+// zero.
// if x>0 result = trunc(x+0.5)
// if x<0 result = trunc(x-0.5)
-// *******************************************************************************
-
-// Set denormal flag for denormal input and
-// and take denormal fault if necessary.
+//
+//==============================================================
-// If x is NAN, ZERO, INFINITY, or >= 2^52 then return
+// double_extended
+// if the exponent is > 1003e => 3F(true) = 63(decimal)
+// we have a significand of 64 bits 1.63-bits.
+// If we multiply by 2^63, we no longer have a fractional part
+// So input is an integer value already.
-// qnan snan inf norm unorm 0 -+
-// 1 1 1 0 0 1 11 0xe7
+// double
+// if the exponent is >= 10033 => 34(true) = 52(decimal)
+// 34 + 3ff = 433
+// we have a significand of 53 bits 1.52-bits. (implicit 1)
+// If we multiply by 2^52, we no longer have a fractional part
+// So input is an integer value already.
+// single
+// if the exponent is > 10016 => 17(true) = 23(decimal)
+// we have a significand of 24 bits 1.23-bits. (implicit 1)
+// If we multiply by 2^23, we no longer have a fractional part
+// So input is an integer value already.
-.align 32
-.global round#
.section .text
-.proc round#
-.align 32
-
+GLOBAL_LIBM_ENTRY(round)
-round:
-
-// Get exponent for +0.5
-// Truncate x to integer
{ .mfi
- addl round_GR_half = 0x0fffe, r0
- fcvt.fx.trunc.s1 ROUND_TRUNC_f8 = f8
- nop.i 999
-}
-
-// Get signexp of x
-// Normalize input
-// Form exponent mask
+ getf.exp rSignexp = f8 // Get signexp, recompute if unorm
+ fcvt.fx.trunc.s1 fXtruncInt = f8 // Convert to int in significand
+ addl rBigexp = 0x10033, r0 // Set exponent at which is integer
+}
{ .mfi
- getf.exp round_GR_signexp = f8
- fnorm ROUND_NORM_f8 = f8
- addl round_GR_expmask = 0x1ffff, r0 ;;
+ mov rExpHalf = 0x0FFFE // Form sign and exponent of 0.5
+ fnorm.s1 fNormX = f8 // Normalize input
+ mov rExpMask = 0x1FFFF // Form exponent mask
}
+;;
-// Form +0.5
-// Round x to integer
{ .mfi
- setf.exp ROUND_HALF = round_GR_half
- fcvt.fx.s1 ROUND_RINT_f8 = f8
- nop.i 999 ;;
+ setf.exp fHalf = rExpHalf // Form 0.5
+ fclass.m p7,p0 = f8, 0x0b // Test x unorm
+ nop.i 0
}
-// Get exp of x
-// Test for NAN, INF, ZERO
-// Get exponent at which input has no fractional part
-{ .mfi
- and round_GR_exp = round_GR_expmask, round_GR_signexp
- fclass.m p8,p9 = f8,0xe7
- addl round_GR_big = 0x10033, r0 ;;
+;;
+
+{ .mfb
+ nop.m 0
+ fclass.m p6,p0 = f8, 0x1e3 // Test x natval, nan, inf
+(p7) br.cond.spnt ROUND_UNORM // Branch if x unorm
}
+;;
-// Get exp-bigexp
-// If exp is so big there is no fractional part, then turn on p8, off p9
-{ .mmi
- sub round_GR_expdiff = round_GR_exp, round_GR_big ;;
-#ifdef _LIBC
-(p9) cmp.lt.or.andcm p8,p9 = r0, round_GR_expdiff
-#else
-(p9) cmp.ge.or.andcm p8,p9 = round_GR_expdiff, r0
-#endif
- nop.i 999 ;;
-}
-
-// Set p6 if x<0, else set p7
-{ .mfi
- nop.m 999
-(p9) fcmp.lt.unc p6,p7 = f8,f0
- nop.i 999
+ROUND_COMMON:
+// Return here from ROUND_UNORM
+{ .mfb
+ nop.m 0
+ fcmp.lt.s1 p8,p9 = f8, f0 // Test if x < 0
+(p6) br.cond.spnt ROUND_SPECIAL // Exit if x natval, nan, inf
}
-
-// If NAN, INF, ZERO, or no fractional part, result is just normalized input
+;;
+
{ .mfi
- nop.m 999
-(p8) fnorm.d.s0 f8 = f8
- nop.i 999 ;;
+ nop.m 0
+ fcvt.xf f8 = fXtruncInt // Pre-Result if 0.5 <= |x| < 2^52
+ nop.i 0
}
+;;
-// Float the truncated integer
{ .mfi
- nop.m 999
-(p9) fcvt.xf ROUND_FLOAT_TRUNC_f8 = ROUND_TRUNC_f8
- nop.i 999 ;;
+ and rExp = rSignexp, rExpMask // Get biased exponent
+ fmerge.s fInc = fNormX, f1 // Form increment if |rem| >= 0.5
+ nop.i 0
}
+;;
-// Float the rounded integer to get preliminary result
-{ .mfi
- nop.m 999
-(p9) fcvt.xf ROUND_FLOAT_RINT_f8 = ROUND_RINT_f8
- nop.i 999 ;;
-}
-
-// If x<0 and the difference of the truncated input minus the input is 0.5
-// then result = truncated input - 1.0
-// Else if x>0 and the difference of the input minus truncated input is 0.5
-// then result = truncated input + 1.0
-// Else
-// result = rounded input
-// Endif
-{ .mfi
- nop.m 999
-(p6) fsub.s1 ROUND_REMAINDER = ROUND_FLOAT_TRUNC_f8, ROUND_NORM_f8
- nop.i 999
+{ .mmi
+ cmp.lt p6,p0 = rExp, rExpHalf // Is |x| < 0.5?
+ cmp.ge p7,p0 = rExp, rBigexp // Is |x| >= 2^52?
+ cmp.lt p10,p0 = rExp, rExpHalf // Is |x| < 0.5?
}
-
+;;
+
+// We must correct result if |x| < 0.5, or |x| >= 2^52
+.pred.rel "mutex",p6,p7
{ .mfi
- nop.m 999
-(p7) fsub.s1 ROUND_REMAINDER = ROUND_NORM_f8, ROUND_FLOAT_TRUNC_f8
- nop.i 999 ;;
+ nop.m 0
+(p6) fmerge.s f8 = fNormX, f0 // If |x| < 0.5, result sgn(x)*0
+ nop.i 0
}
+{ .mfb
+(p7) cmp.eq p10,p0 = r0, r0 // Also turn on p10 if |x| >= 2^52
+(p7) fma.d.s0 f8 = fNormX, f1, f0 // If |x| >= 2^52, result x
+(p10) br.ret.spnt b0 // Exit |x| < 0.5 or |x| >= 2^52
+}
+;;
-// Assume preliminary result is rounded integer
+// Here if 0.5 <= |x| < 2^52
{ .mfi
- nop.m 999
-(p9) fnorm.d.s0 f8 = ROUND_FLOAT_RINT_f8
- nop.i 999
+ nop.m 0
+(p9) fms.s1 fRem = fNormX, f1, f8 // Get remainder = x - trunc(x)
+ nop.i 0
}
-
-// If x<0, test if result=0
{ .mfi
- nop.m 999
-(p6) fcmp.eq.unc p10,p0 = ROUND_FLOAT_RINT_f8,f0
- nop.i 999 ;;
+ nop.m 0
+(p8) fms.s1 fRem = f8, f1, fNormX // Get remainder = trunc(x) - x
+ nop.i 0
}
+;;
-// If x<0 and result=0, set result=-0
{ .mfi
- nop.m 999
-(p10) fmerge.ns f8 = f1,f8
- nop.i 999
+ nop.m 0
+ fcmp.ge.s1 p9,p0 = fRem, fHalf // Test |rem| >= 0.5
+ nop.i 0
}
-
-// If x<0, test if remainder=0.5
-{ .mfi
- nop.m 999
-(p6) fcmp.eq.unc p6,p0 = ROUND_REMAINDER, ROUND_HALF
- nop.i 999 ;;
+;;
+
+// If x < 0 and remainder <= -0.5, then subtract 1 from result
+// If x > 0 and remainder >= +0.5, then add 1 to result
+{ .mfb
+ nop.m 0
+(p9) fma.d.s0 f8 = f8, f1, fInc
+ br.ret.sptk b0
}
-
-// If x>0, test if remainder=0.5
-{ .mfi
- nop.m 999
-(p7) fcmp.eq.unc p7,p0 = ROUND_REMAINDER, ROUND_HALF
- nop.i 999 ;;
+;;
+
+
+ROUND_SPECIAL:
+// Here if x natval, nan, inf
+{ .mfb
+ nop.m 0
+ fma.d.s0 f8 = f8, f1, f0
+ br.ret.sptk b0
}
+;;
-// If x<0 and remainder=0.5, result=truncated-1.0
-// If x>0 and remainder=0.5, result=truncated+1.0
-// Exit
-.pred.rel "mutex",p6,p7
+ROUND_UNORM:
+// Here if x unorm
{ .mfi
- nop.m 999
-(p6) fsub.d.s0 f8 = ROUND_FLOAT_TRUNC_f8,f1
- nop.i 999
+ getf.exp rSignexp = fNormX // Get signexp, recompute if unorm
+ fcmp.eq.s0 p7,p0 = f8, f0 // Dummy op to set denormal flag
+ nop.i 0
}
-
{ .mfb
- nop.m 999
-(p7) fadd.d.s0 f8 = ROUND_FLOAT_TRUNC_f8,f1
- br.ret.sptk b0 ;;
+ nop.m 0
+ fcvt.fx.trunc.s1 fXtruncInt = fNormX // Convert to int in significand
+ br.cond.sptk ROUND_COMMON // Return to main path
}
+;;
-.endp round
-ASM_SIZE_DIRECTIVE(round)
+GLOBAL_LIBM_END(round)