.file "logbl.s"
-// Copyright (C) 2000, 2001, Intel Corporation
+
+// Copyright (c) 2000 - 2003, Intel Corporation
// All rights reserved.
-//
-// Contributed 2/2/2000 by John Harrison, Ted Kubaska, Bob Norin, 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
// * 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
//==============================================================
-// 2/02/00 Initial version
-// 2/16/00 Modified to conform to C9X
-// 3/16/00 Improved speed
-// 4/04/00 Unwind support added
-// 5/30/00 Fixed bug when x double-extended denormal
-// 8/15/00 Bundle added after call to __libm_error_support to properly
+// 02/02/00 Initial version
+// 02/16/00 Modified to conform to C9X
+// 03/16/00 Improved speed
+// 04/04/00 Unwind support added
+// 05/30/00 Fixed bug when x double-extended denormal
+// 08/15/00 Bundle added after call to __libm_error_support to properly
// set [the previously overwritten] GR_Parameter_RESULT.
+// 05/20/02 Cleaned up namespace and sf0 syntax
+// 01/20/03 Improved performance
//
// API
//==============================================================
-// long double logbl( long double x);
+// long double logbl( long double x );
//
// Overview of operation
//==============================================================
-// The logbl function extracts the exponent of x as an integer in
-// floating-point format.
+// The logbl function extracts the exponent of x as an integer in
+// floating-point format.
// logbl computes log2 of x as a long double
//
-// logbl is similar to ilogbl but differs in the following ways:
+// logbl is similar to ilogbl but differs in the following ways:
// +-inf
// ilogbl: returns INT_MAX
// logbl: returns +inf
//
// Registers used
//==============================================================
-// general registers used:
-// ar.pfs r32
-// r33 -> r37
-// r38 -> r41 used as parameters to error path
+// general registers used:
+// r26 -> r38
+// r35 -> r38 used as parameters to error path
//
-// predicate registers used:
+// predicate registers used:
// p6, p7, p8
-//
-// floating-point registers used:
+// floating-point registers used:
// f9, f10, f11
// f8, input
-#include "libm_support.h"
+rExpBias = r26
+rExpMask = r27
+rSignexp_x = r28
+rExp_x = r29
+rTrueExp_x = r30
+rExp_2to64 = r31
GR_SAVE_PFS = r32
-GR_SAVE_B0 = r34
-GR_SAVE_GP = r35
-GR_Parameter_X = r38
-GR_Parameter_Y = r39
-GR_Parameter_RESULT = r40
-GR_Parameter_TAG = r41
+GR_SAVE_B0 = r33
+GR_SAVE_GP = r34
-FR_X = f8
-FR_Y = f0
-FR_RESULT = f10
+GR_Parameter_X = r35
+GR_Parameter_Y = r36
+GR_Parameter_RESULT = r37
+GR_Parameter_TAG = r38
-.align 32
-.global logbl#
+fExp_in_signif = f9
+fNorm_x = f10
+fFloat_Exp = f10
+f2to64 = f11
.section .text
-.proc logbl#
-.align 32
-
+GLOBAL_LIBM_ENTRY(logbl)
-logbl:
-
-// qnan snan inf norm unorm 0 -+
-// 0 0 0 0 1 0 11
-// 0 b
-{ .mfi
- alloc r32=ar.pfs,1,5,4,0
-(p0) fclass.m.unc p8,p0 = f8, 0x0b
- nop.i 999
-}
// X NORMAL
-// r37 = exp(f8) - - 0xffff
-// sig(f8) = r37
+// TrueExp_x = exp(f8) - 0xffff
+// sig = TrueExp_x
// f8 = convert_to_fp (sig))
{ .mfi
-(p0) getf.exp r35 = f8
-(p0) fnorm f10=f8
- nop.i 999 ;;
+ getf.exp rSignexp_x = f8
+ fclass.m p8,p0 = f8, 0x0b // Test for x unorm
+ mov rExpBias = 0xffff // Exponent bias
}
-
-// qnan snan inf norm unorm 0 -+
-// 1 1 1 0 0 0 11
-// e 3
-{ .mmf
-(p0) mov r33 = 0xffff
-(p0) mov r34 = 0x1ffff
-(p0) fclass.m.unc p6,p0 = f8, 0xe3 ;;
+{ .mfi
+ nop.m 0
+ fnorm.s1 fNorm_x = f8
+ mov rExpMask = 0x1ffff // Exponent mask
}
+;;
+// Form signexp of 2^64 in case need to scale denormal
{ .mfb
-(p0) and r36 = r35, r34
-(p0) fclass.m.unc p7,p0 = f8, 0x07
-(p8) br.cond.spnt L(LOGB_DENORM) ;;
+ mov rExp_2to64 = 0x1003f
+ fclass.m p6,p0 = f8, 0x1e3 // Test x natval, nan, inf
+(p8) br.cond.spnt LOGB_DENORM // Branch if x unorm
}
+;;
-{ .mib
-(p0) sub r37 = r36, r33
- nop.i 999
-(p6) br.cond.spnt L(LOGB_NAN_INF) ;;
+LOGB_COMMON:
+// Return here from LOGB_DENORM
+{ .mfi
+ and rExp_x = rSignexp_x, rExpMask // Get biased exponent
+ fclass.m p7,p0 = f8, 0x07 // Test x zero
+ nop.i 0
}
+;;
+
+// X NAN or INFINITY, return f8 * f8
+{ .mfb
+ sub rTrueExp_x = rExp_x, rExpBias // Get true exponent
+(p6) fma.s0 f8= f8,f8,f0 // Result if x natval, nan, inf
+(p6) br.ret.spnt b0 // Exit if x natval, nan, inf
+}
+;;
{ .mib
-(p0) setf.sig f9 = r37
+ setf.sig fExp_in_signif = rTrueExp_x // Exponent as integer in fp
nop.i 999
-(p7) br.cond.spnt L(LOGB_ZERO) ;;
-}
-{ .mfi
- nop.m 999
-(p0) fcvt.xf f10 = f9
- nop.i 999 ;;
+(p7) br.cond.spnt LOGB_ZERO
}
+;;
+// Result can be represented in less than 24 bits, so no precision completer
+// is needed.
{ .mfb
- nop.m 999
-(p0) fnorm f8 = f10
-(p0) br.ret.sptk b0 ;;
+ nop.m 0
+ fcvt.xf f8 = fExp_in_signif
+ br.ret.sptk b0 // Exit main path, 0 < |x| < inf
}
+;;
-L(LOGB_DENORM):
-// Form signexp of 2^64 in case need to scale denormal
+LOGB_DENORM:
+// Form 2^64 in case need to scale denormal
// Check to see if double-extended denormal
{ .mfi
-(p0) mov r38 = 0x1003f
-(p0) fclass.m.unc p8,p0 = f10, 0x0b
- nop.i 999 ;;
+ setf.exp f2to64 = rExp_2to64
+ fclass.m p8,p0 = fNorm_x, 0x0b
+ nop.i 0
}
+;;
-// Form 2^64 in case need to scale denormal
{ .mfi
-(p0) setf.exp f11 = r38
- nop.f 999
- nop.i 999 ;;
+ nop.m 0
+ fcmp.eq.s0 p7,p0 = f8, f0 // Dummy op to set denormal flag
+ nop.i 0
}
+;;
// If double-extended denormal add 64 to exponent bias for scaling
// If double-extended denormal form x * 2^64 which is normal
{ .mfi
-(p8) add r33 = 64, r33
-(p8) fmpy f10 = f10, f11
- nop.i 999 ;;
+(p8) add rExpBias = 64, rExpBias
+(p8) fmpy.s1 fNorm_x = fNorm_x, f2to64
+ nop.i 0
}
+;;
// Logic is the same as normal path but use normalized input
-{ .mmi
-(p0) getf.exp r35 = f10 ;;
- nop.m 999
- nop.i 999 ;;
+{ .mib
+ getf.exp rSignexp_x = fNorm_x
+ nop.i 0
+ br.cond.sptk LOGB_COMMON // Return to main path
}
+;;
-{ .mmi
-(p0) and r36 = r35, r34 ;;
-(p0) sub r37 = r36, r33
- nop.i 999 ;;
-}
+LOGB_ZERO:
+// Here if x zero
+// f10 = -|f8|
+// f9 = 1.0/f10 = -1.0/|f8| = -inf
-{ .mmi
-(p0) setf.sig f9 = r37
- nop.m 999
- nop.i 999 ;;
-}
-
-{ .mfi
- nop.m 999
-(p0) fcvt.xf f10 = f9
- nop.i 999 ;;
+{ .mmf
+ alloc r32=ar.pfs,1,2,4,0
+ mov GR_Parameter_TAG = 150 // Error code
+ fmerge.ns f10 = f0,f8
}
+;;
{ .mfb
- nop.m 999
-(p0) fnorm f8 = f10
-(p0) br.ret.sptk b0 ;;
+ nop.m 0
+ frcpa.s0 f9,p6 = f1,f10 // Produce -inf, Z flag
+ br.cond.sptk __libm_error_region // Call error support
}
+;;
-L(LOGB_NAN_INF):
-
-// X NAN or INFINITY, return f8 * f8
-{ .mfb
- nop.m 999
-(p0) fma f8= f8,f8,f0
-(p0) br.ret.sptk b0 ;;
-}
+GLOBAL_LIBM_END(logbl)
-L(LOGB_ZERO):
-{.mfi
- nop.m 0
-(p0) frcpa.s0 f10,p6 = f1,f0
- nop.i 0
-};;
-{.mfi
- mov GR_Parameter_TAG = 150
-(p0) fms.s1 f10 = f0,f0,f10
- nop.i 0
-};;
-// X ZERO
-// return -1.0/fabs(f8)=-inf, set divide-by-zero flag, call error support
-.endp logbl
-ASM_SIZE_DIRECTIVE(logbl)
-.proc __libm_error_region
-__libm_error_region:
+LOCAL_LIBM_ENTRY(__libm_error_region)
.prologue
+
{ .mfi
- add GR_Parameter_Y=-32,sp // Parameter 2 value
+ add GR_Parameter_Y=-32,sp // Parameter 2 value
nop.f 0
.save ar.pfs,GR_SAVE_PFS
- mov GR_SAVE_PFS=ar.pfs // Save ar.pfs
+ mov GR_SAVE_PFS=ar.pfs // Save ar.pfs
}
{ .mfi
.fframe 64
- add sp=-64,sp // Create new stack
+ add sp=-64,sp // Create new stack
nop.f 0
- mov GR_SAVE_GP=gp // Save gp
+ mov GR_SAVE_GP=gp // Save gp
};;
+
{ .mmi
- stfe [GR_Parameter_Y] = FR_Y,16 // Save Parameter 2 on stack
- add GR_Parameter_X = 16,sp // Parameter 1 address
+ stfe [GR_Parameter_Y] = f0,16 // STORE Parameter 2 on stack
+ add GR_Parameter_X = 16,sp // Parameter 1 address
.save b0, GR_SAVE_B0
- mov GR_SAVE_B0=b0 // Save b0
+ mov GR_SAVE_B0=b0 // Save b0
};;
+
.body
{ .mib
- stfe [GR_Parameter_X] = FR_X // Store Parameter 1 on stack
- add GR_Parameter_RESULT = 0,GR_Parameter_Y
- nop.b 0 // Parameter 3 address
+ stfe [GR_Parameter_X] = f8 // STORE Parameter 1 on stack
+ add GR_Parameter_RESULT = 0,GR_Parameter_Y // Parameter 3 address
+ nop.b 0
}
{ .mib
- stfe [GR_Parameter_Y] = FR_RESULT // Store Parameter 3 on stack
+ stfe [GR_Parameter_Y] = f9 // Store Parameter 3 on stack
add GR_Parameter_Y = -16,GR_Parameter_Y
- br.call.sptk b0=__libm_error_support# // Call error handling function
+ br.call.sptk b0=__libm_error_support# // Call error handling function
};;
+
{ .mmi
- nop.m 0
- nop.m 0
add GR_Parameter_RESULT = 48,sp
+ nop.m 0
+ nop.i 0
};;
+
{ .mmi
ldfe f8 = [GR_Parameter_RESULT] // Get return result off stack
.restore sp
add sp = 64,sp // Restore stack pointer
mov b0 = GR_SAVE_B0 // Restore return address
};;
+
{ .mib
mov gp = GR_SAVE_GP // Restore gp
mov ar.pfs = GR_SAVE_PFS // Restore ar.pfs
- br.ret.sptk b0 // Return
+ br.ret.sptk b0
};;
-.endp __libm_error_region
-ASM_SIZE_DIRECTIVE(__libm_error_region)
+LOCAL_LIBM_END(__libm_error_region)
+
.type __libm_error_support#,@function
.global __libm_error_support#
git.samba.org / jlayton / glibc.git / blobdiff