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authorMike Frysinger <vapier@gentoo.org>2014-02-15 22:07:25 -0500
committerMike Frysinger <vapier@gentoo.org>2014-02-16 01:12:38 -0500
commitc70a4b1db0cf5e813ae24b0fa96a352399eb6edf (patch)
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ia64: relocate out of ports/ subdir
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+.file "logb.s"
+
+
+// Copyright (c) 2000 - 2003, Intel Corporation
+// All rights reserved.
+//
+// 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
+// met:
+//
+// * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//
+// * Redistributions in binary form must reproduce the above copyright
+// notice, this list of conditions and the following disclaimer in the
+// documentation and/or other materials provided with the distribution.
+//
+// * 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
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// 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
+// 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.
+//
+// Intel Corporation is the author of this code, and requests that all
+// problem reports or change requests be submitted to it directly at
+// http://www.intel.com/software/products/opensource/libraries/num.htm.
+//
+// History
+//==============================================================
+// 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
+//==============================================================
+// double logb( double x );
+//
+// Overview of operation
+//==============================================================
+// The logb function extracts the exponent of x as an integer in
+// floating-point format.
+// logb computes log2 of x as a double
+//
+// logb is similar to ilogb but differs in the following ways:
+// +-inf
+// ilogb: returns INT_MAX
+// logb: returns +inf
+// Nan returns FP_LOGBNAN (which is either INT_MAX or INT_MIN)
+// ilogb: returns INT_MAX (7fffffff)
+// logb: returns QNAN (quietized SNAN)
+// 0 returns FP_ILOGB0 (which is either INT_MIN or -INT_MAX)
+// ilogb: returns -INT_MAX (80000001)
+// logb: returns -inf, raises the divide-by-zero exception,
+// and calls libm_error_support to set domain error
+//
+// Registers used
+//==============================================================
+// general registers used:
+// r26 -> r38
+// r35 -> r38 used as parameters to error path
+//
+// predicate registers used:
+// p6, p7, p8
+// floating-point registers used:
+// f9, f10, f11
+// f8, input
+
+rExpBias = r26
+rExpMask = r27
+rSignexp_x = r28
+rExp_x = r29
+rTrueExp_x = r30
+rExp_2to64 = r31
+
+GR_SAVE_PFS = r32
+GR_SAVE_B0 = r33
+GR_SAVE_GP = r34
+
+GR_Parameter_X = r35
+GR_Parameter_Y = r36
+GR_Parameter_RESULT = r37
+GR_Parameter_TAG = r38
+
+fExp_in_signif = f9
+fNorm_x = f10
+fFloat_Exp = f10
+f2to64 = f11
+
+.section .text
+GLOBAL_LIBM_ENTRY(logb)
+
+// X NORMAL
+// TrueExp_x = exp(f8) - 0xffff
+// sig = TrueExp_x
+// f8 = convert_to_fp (sig))
+{ .mfi
+ getf.exp rSignexp_x = f8
+ fclass.m p8,p0 = f8, 0x0b // Test for x unorm
+ mov rExpBias = 0xffff // Exponent bias
+}
+{ .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
+ 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
+}
+;;
+
+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.d.s0 f8= f8,f8,f0 // Result if x natval, nan, inf
+(p6) br.ret.spnt b0 // Exit if x natval, nan, inf
+}
+;;
+
+{ .mib
+ setf.sig fExp_in_signif = rTrueExp_x // Exponent as integer in fp
+ 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 0
+ fcvt.xf f8 = fExp_in_signif
+ br.ret.sptk b0 // Exit main path, 0 < |x| < inf
+}
+;;
+
+LOGB_DENORM:
+// Form 2^64 in case need to scale denormal
+// Check to see if double-extended denormal
+{ .mfi
+ setf.exp f2to64 = rExp_2to64
+ fclass.m p8,p0 = fNorm_x, 0x0b
+ nop.i 0
+}
+;;
+
+{ .mfi
+ 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 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
+{ .mib
+ getf.exp rSignexp_x = fNorm_x
+ nop.i 0
+ br.cond.sptk LOGB_COMMON // Return to main path
+}
+;;
+
+LOGB_ZERO:
+// Here if x zero
+// f10 = -|f8|
+// f9 = 1.0/f10 = -1.0/|f8| = -inf
+
+{ .mmf
+ alloc r32=ar.pfs,1,2,4,0
+ mov GR_Parameter_TAG = 151 // Error code
+ fmerge.ns f10 = f0,f8
+}
+;;
+
+{ .mfb
+ nop.m 0
+ frcpa.s0 f9,p6 = f1,f10 // Produce -inf, Z flag
+ br.cond.sptk __libm_error_region // Call error support
+}
+;;
+
+GLOBAL_LIBM_END(logb)
+
+
+LOCAL_LIBM_ENTRY(__libm_error_region)
+.prologue
+
+{ .mfi
+ 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
+}
+{ .mfi
+.fframe 64
+ add sp=-64,sp // Create new stack
+ nop.f 0
+ mov GR_SAVE_GP=gp // Save gp
+};;
+
+{ .mmi
+ stfd [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
+};;
+
+.body
+{ .mib
+ stfd [GR_Parameter_X] = f8 // STORE Parameter 1 on stack
+ add GR_Parameter_RESULT = 0,GR_Parameter_Y // Parameter 3 address
+ nop.b 0
+}
+{ .mib
+ stfd [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
+};;
+
+{ .mmi
+ add GR_Parameter_RESULT = 48,sp
+ nop.m 0
+ nop.i 0
+};;
+
+{ .mmi
+ ldfd 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
+};;
+
+LOCAL_LIBM_END(__libm_error_region)
+
+
+.type __libm_error_support#,@function
+.global __libm_error_support#