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Diffstat (limited to 'sysdeps/ia64/fpu/s_logb.S')
| -rw-r--r-- | sysdeps/ia64/fpu/s_logb.S | 314 |
1 files changed, 314 insertions, 0 deletions
diff --git a/sysdeps/ia64/fpu/s_logb.S b/sysdeps/ia64/fpu/s_logb.S new file mode 100644 index 0000000000..d24f1f6497 --- /dev/null +++ b/sysdeps/ia64/fpu/s_logb.S @@ -0,0 +1,314 @@ +.file "logb.s" + +// Copyright (c) 2000, 2001, 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. +// +// WARRANTY DISCLAIMER +// +// 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://developer.intel.com/opensource. +// +// 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 +// set [the previously overwritten] GR_Parameter_RESULT. +// +// 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: +// ar.pfs r32 +// r33 -> r37 +// r38 -> r41 used as parameters to error path +// +// predicate registers used: +// p6, p7, p8 +// floating-point registers used: +// f9, f10, f11 +// f8, input + +#include "libm_support.h" + +GR_SAVE_B0 = r34 +GR_SAVE_GP = r35 +GR_SAVE_PFS = r32 + +GR_Parameter_X = r38 +GR_Parameter_Y = r39 +GR_Parameter_RESULT = r40 + +.align 32 +.global logb# + +.section .text +.proc logb# +.align 32 + + +logb: + +// 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 +// f8 = convert_to_fp (sig)) +{ .mfi +(p0) getf.exp r35 = f8 +(p0) fnorm f10=f8 + nop.i 999 ;; +} + +// 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 ;; +} + +{ .mfb +(p0) and r36 = r35, r34 +(p0) fclass.m.unc p7,p0 = f8, 0x07 +(p8) br.cond.spnt L(LOGB_DENORM) ;; +} + +{ .mib +(p0) sub r37 = r36, r33 + nop.i 999 +(p6) br.cond.spnt L(LOGB_NAN_INF) ;; +} + +{ .mib +(p0) setf.sig f9 = r37 + nop.i 999 +(p7) br.cond.spnt L(LOGB_ZERO) ;; +} + +{ .mfi + nop.m 999 +(p0) fcvt.xf f10 = f9 + nop.i 999 ;; +} + +{ .mfb + nop.m 999 +(p0) fnorm.d f8 = f10 +(p0) br.ret.sptk b0 ;; +} + +L(LOGB_DENORM): +// Form signexp of 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 ;; +} + +// Form 2^64 in case need to scale denormal +{ .mfi +(p0) setf.exp f11 = r38 + nop.f 999 + nop.i 999 ;; +} + +// 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 ;; +} + +// Logic is the same as normal path but use normalized input +{ .mmi +(p0) getf.exp r35 = f10 ;; + nop.m 999 + nop.i 999 ;; +} + +{ .mmi +(p0) and r36 = r35, r34 ;; +(p0) sub r37 = r36, r33 + nop.i 999 ;; +} + +{ .mmi +(p0) setf.sig f9 = r37 + nop.m 999 + nop.i 999 ;; +} + +{ .mfi + nop.m 999 +(p0) fcvt.xf f10 = f9 + nop.i 999 ;; +} + +{ .mfb + nop.m 999 +(p0) fnorm.d f8 = f10 +(p0) br.ret.sptk b0 ;; +} + +L(LOGB_NAN_INF): + +// X NAN or INFINITY, return f8 * f8 +{ .mfb + nop.m 999 +(p0) fma.d f8= f8,f8,f0 +(p0) br.ret.sptk b0 ;; +} + +.endp logb# +ASM_SIZE_DIRECTIVE(logb) + +// Stack operations when calling error support. +// (1) (2) (3) (call) (4) +// sp -> + psp -> + psp -> + sp -> + +// | | | | +// | | <- GR_Y R3 ->| <- GR_RESULT | -> f8 +// | | | | +// | <-GR_Y Y2->| Y2 ->| <- GR_Y | +// | | | | +// | | <- GR_X X1 ->| | +// | | | | +// sp-64 -> + sp -> + sp -> + + +// save ar.pfs save b0 restore gp +// save gp restore ar.pfs + + + +.proc __libm_error_region +__libm_error_region: +L(LOGB_ZERO): +.prologue + +// f9 = |f8| +// f10 = -f9 = -|f8| +// f9 = 1.0/f10 = -1.0/-|f8| + +{ .mfi + mov r41 = 151 // Error code +(p0) fmerge.s f9 = f0,f8 + nop.i 999 +} +;; + + +{ .mfi + nop.m 999 + fmerge.ns f10 = f0,f9 + nop.i 999 +} +;; + +// (1) +{ .mfi + add GR_Parameter_Y=-32,sp // Parameter 2 value + frcpa f9,p6 = f1,f10 +.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 +};; + + +// (2) +{ .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 +// (3) +{ .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 + nop.m 0 + nop.m 0 + add GR_Parameter_RESULT = 48,sp +};; + +// (4) +{ .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 +};; + +.endp __libm_error_region +ASM_SIZE_DIRECTIVE(__libm_error_region) + +.type __libm_error_support#,@function +.global __libm_error_support# |