aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
Diffstat (limited to 'sysdeps/ia64/fpu/s_ilogb.S')
-rw-r--r--sysdeps/ia64/fpu/s_ilogb.S305
1 files changed, 160 insertions, 145 deletions
diff --git a/sysdeps/ia64/fpu/s_ilogb.S b/sysdeps/ia64/fpu/s_ilogb.S
index 61975dd941..0102370cd6 100644
--- a/sysdeps/ia64/fpu/s_ilogb.S
+++ b/sysdeps/ia64/fpu/s_ilogb.S
@@ -1,10 +1,10 @@
.file "ilogb.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
@@ -20,234 +20,249 @@
// * 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
//==============================================================
-// 2/03/00 Initial version
-// 5/26/00 Fix bug when x a double-extended denormal;
+// 02/03/00 Initial version
+// 05/26/00 Fix bug when x a double-extended denormal;
// if x=0 call error routine, per C9X
-// 8/15/00 Bundle added after call to __libm_error_support to properly
+// 08/15/00 Bundle added after call to __libm_error_support to properly
// set [the previously overwritten] GR_Parameter_RESULT.
-// 1/20/01 Fixed result for x=0, corrected error tag value.
-
-.align 32
-.global ilogb#
-
-.section .text
-.proc ilogb#
-.align 32
-
+// 01/20/01 Fixed result for x=0, corrected error tag value.
+// 05/20/02 Cleaned up namespace and sf0 syntax
+// 01/20/03 Improved performance
+//
// API
//==============================================================
-// int = ilogb(double)
-
+// int ilogb( double x );
+//
// Overview of operation
//==============================================================
-// ilogb computes log2(x) as an int
+// The ilogb function extracts the exponent of x as an integer
// and returns it in r8
-
-// ilogb is similar to logb but differs in the following ways:
+//
+// ilogb is similar to logb but differs in the following ways:
// +-inf
// ilogb: returns INT_MAX
// logb: returns +inf
-// Nan returns FP_ILOGBNAN (which is either INT_MAX or INT_MIN)
+// Nan returns FP_LOGBNAN (which is either INT_MAX or INT_MIN)
// ilogb: returns INT_MAX (7fffffff)
-// logb: returns QNAN (quieted SNAN)
+// logb: returns QNAN (quietized SNAN)
// 0 returns FP_ILOGB0 (which is either INT_MIN or -INT_MAX)
-// ilogb: returns INT_MIN (80000000)
-// logb: returns -inf
-
+// 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 -> r39
+// r36 -> r39 used as parameters to error path
+//
+// predicate registers used:
+// p6 -> p10
+// floating-point registers used:
+// f9, f10, f11
+// f8, input
-// general local registers:
-// ar.pfs r32
-// r33 -> r37
-// r38 -> r41 used as parameters to error path
-
-// predicate registers used:
-// p6 - x nan, inf
-// p7 - x 0
-// p8 - x norm, unorm
-// p9 - x unorm
-
-// floating-point registers used:
-// f8 - f10
-
-#include "libm_support.h"
+rExpBias = r26
+rExpMask = r27
+rSignexp_x = r28
+rExp_x = r29
+rIntMax = r30
+rExp_2to64 = r31
GR_SAVE_PFS = r32
+rTrialResult = r33
GR_SAVE_B0 = r34
GR_SAVE_GP = r35
-GR_Parameter_X = r38
-GR_Parameter_Y = r39
-GR_Parameter_RESULT = r40
-GR_Parameter_TAG = r41
-FR_X = f8
-FR_Y = f0
-FR_RESULT = f0
+GR_Parameter_X = r36
+GR_Parameter_Y = r37
+GR_Parameter_RESULT = r38
+GR_Parameter_TAG = r39
+fTmp = f9
+fNorm_x = f10
+f2to64 = f11
-ilogb:
+.section .text
+GLOBAL_LIBM_ENTRY(ilogb)
-// Form signexp of 2^64 in case need to scale denormal
-{ .mmf
- alloc r32=ar.pfs,1,5,4,0
-(p0) mov r37 = 0x1003f
-(p0) fnorm f9 = f8 ;;
+// X NORMAL
+// TrueExp_x = exp(f8) - 0xffff
+// r8 = TrueExp_x
+{ .mfi
+ getf.exp rSignexp_x = f8
+ fclass.m p8,p0 = f8, 0x0b // Test for x unorm
+ mov rExpBias = 0xffff // Exponent bias
}
-
-// Form 2^64 in case need to scale denormal
{ .mfi
-(p0) setf.exp f10 = r37
-(p0) fclass.m.unc p7, p8 = f8, 0xe3
-(p0) mov r34 = 0xffff ;;
+ nop.m 0
+ fnorm.s1 fNorm_x = f8
+ mov rExpMask = 0x1ffff // Exponent mask
}
+;;
-// qnan snan inf norm unorm 0 -+
-// 1 1 1 0 0 0 11
-// e 3
-// X ZERO, returns INT_MIN
-// X INF or NAN, returns INT_MAX
+// Form signexp of 2^64 in case need to scale denormal
+{ .mfb
+ mov rExp_2to64 = 0x1003f
+ fclass.m p6,p9 = f8, 0x1e3 // Test x natval, nan, inf
+(p8) br.cond.spnt ILOGB_DENORM // Branch if x unorm
+}
+;;
+ILOGB_COMMON:
+// Return here from ILOGB_DENORM
{ .mfi
-(p0) mov r35 = 0x1ffff
-(p8) fclass.m.unc p6, p8 = f8, 0x07
- nop.i 999 ;;
+ and rExp_x = rSignexp_x, rExpMask // Get biased exponent
+ fclass.m p7,p10 = f8, 0x07 // Test x zero
+ nop.i 0
}
{ .mlx
- nop.m 999
-(p7) movl r8 = 0x000000007fffffff ;;
+ nop.m 0
+ movl rIntMax = 0x000000007fffffff // Form INT_MAX
}
+;;
-{ .mib
- nop.m 999
- nop.i 999
-(p6) br.cond.spnt L(ILOGB_ZERO) ;;
+.pred.rel "mutex",p6,p9
+{ .mfi
+(p9) sub r8 = rExp_x, rExpBias // Get true exponent for normal path
+(p6) fma.s0 fTmp = f8, f8, f0 // Dummy to set Invalid flag
+(p6) mov r8 = rIntMax // If nan, inf, return INT_MAX
}
+{ .mbb
+ nop.m 0
+(p7) br.cond.spnt ILOGB_ZERO // Branch if x zero
+(p10) br.ret.sptk b0 // Exit if x not zero
+}
+;;
+
-// Test for denormal
+ILOGB_DENORM:
+// Form 2^64 in case need to scale denormal
+// Check to see if double-extended denormal
{ .mfi
- nop.m 999
-(p8) fclass.m.unc p9, p0 = f9, 0x0b
- nop.i 999 ;;
+ setf.exp f2to64 = rExp_2to64
+ fclass.m p8,p0 = fNorm_x, 0x0b
+ nop.i 0
}
+;;
-L(ILOGB_COMMON):
-// X NORMAL returns true exponent
-{ .mmi
- nop.m 999
-(p8) getf.exp r33 = f9
- nop.i 999 ;;
+{ .mfi
+ nop.m 0
+ fcmp.eq.s0 p7,p0 = f8, f0 // Dummy op to set denormal flag
+ nop.i 0
}
+;;
-// If denormal add 64 to exponent bias for scaling
-{ .mfb
-(p9) add r34 = 64, r34
- nop.f 999
-(p9) br.cond.spnt L(ILOGB_DENORM) ;;
+// 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
}
+;;
-{ .mmi
-(p8) and r36 = r35, r33
- nop.m 999
- nop.i 999 ;;
+// Logic is the same as normal path but use normalized input
+{ .mib
+ getf.exp rSignexp_x = fNorm_x
+ nop.i 0
+ br.cond.sptk ILOGB_COMMON // Return to main path
}
+;;
+ILOGB_ZERO:
+// Here if x zero
+// Return INT_MIN, call error support
+
+{ .mlx
+ alloc r32=ar.pfs,1,3,4,0
+ movl rTrialResult = 0x0000000080000000
+}
{ .mib
-(p8) sub r8 = r36, r34
- nop.i 999
-(p0) br.ret.sptk b0 ;;
+ mov GR_Parameter_TAG = 157 // Error code
+ nop.i 0
+ br.cond.sptk __libm_error_region // Call error support
}
+;;
-L(ILOGB_DENORM):
-// Here if x denormal
-// Form x * 2^64 which is normal
-// Return to common code
-{ .mfb
- cmp.eq p8,p9 = r0,r0
- fmpy f9 = f9, f10
- br.cond.sptk L(ILOGB_COMMON) ;;
-}
+GLOBAL_LIBM_END(ilogb)
-// X ZERO
-// return INT_MIN, call error support
-L(ILOGB_ZERO):
-{.mlx
- mov GR_Parameter_TAG = 157
-(p6) movl r33 = 0x0000000080000000 ;;
-};;
-.endp ilogb
-ASM_SIZE_DIRECTIVE(ilogb)
-.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
- stfd [GR_Parameter_Y] = FR_Y,16 // Save Parameter 2 on stack
- add GR_Parameter_X = 16,sp // Parameter 1 address
+ 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
+ mov GR_SAVE_B0=b0 // Save b0
};;
+
.body
{ .mib
- stfd [GR_Parameter_X] = FR_X // Store Parameter 1 on stack
- add GR_Parameter_RESULT = 0,GR_Parameter_Y
- nop.b 0 // Parameter 3 address
+ 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] = FR_RESULT // Store Parameter 3 on stack
+ 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
+ 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
- mov r8 = r33 // Store result
+ mov r8 = rTrialResult
.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#