From 01629105c2817a59a4f1f05039593f211cf5ddaa Mon Sep 17 00:00:00 2001 From: Joel Sherrill Date: Mon, 14 Dec 1998 23:15:38 +0000 Subject: Patch from Ralf Corsepius to rename all .s files to .S in conformance with GNU conventions. This is a minor step along the way to supporting automake. --- c/src/lib/libcpu/m68k/m68040/fpsp/slog2.S | 190 ++++++++++++++++++++++++++++++ 1 file changed, 190 insertions(+) create mode 100644 c/src/lib/libcpu/m68k/m68040/fpsp/slog2.S (limited to 'c/src/lib/libcpu/m68k/m68040/fpsp/slog2.S') diff --git a/c/src/lib/libcpu/m68k/m68040/fpsp/slog2.S b/c/src/lib/libcpu/m68k/m68040/fpsp/slog2.S new file mode 100644 index 0000000000..42c70092fa --- /dev/null +++ b/c/src/lib/libcpu/m68k/m68040/fpsp/slog2.S @@ -0,0 +1,190 @@ +// +// $Id$ +// +// slog2.sa 3.1 12/10/90 +// +// The entry point slog10 computes the base-10 +// logarithm of an input argument X. +// slog10d does the same except the input value is a +// denormalized number. +// sLog2 and sLog2d are the base-2 analogues. +// +// INPUT: Double-extended value in memory location pointed to +// by address register a0. +// +// OUTPUT: log_10(X) or log_2(X) returned in floating-point +// register fp0. +// +// ACCURACY and MONOTONICITY: The returned result is within 1.7 +// ulps in 64 significant bit, i.e. within 0.5003 ulp +// to 53 bits if the result is subsequently rounded +// to double precision. The result is provably monotonic +// in double precision. +// +// SPEED: Two timings are measured, both in the copy-back mode. +// The first one is measured when the function is invoked +// the first time (so the instructions and data are not +// in cache), and the second one is measured when the +// function is reinvoked at the same input argument. +// +// ALGORITHM and IMPLEMENTATION NOTES: +// +// slog10d: +// +// Step 0. If X < 0, create a NaN and raise the invalid operation +// flag. Otherwise, save FPCR in D1; set FpCR to default. +// Notes: Default means round-to-nearest mode, no floating-point +// traps, and precision control = double extended. +// +// Step 1. Call slognd to obtain Y = log(X), the natural log of X. +// Notes: Even if X is denormalized, log(X) is always normalized. +// +// Step 2. Compute log_10(X) = log(X) * (1/log(10)). +// 2.1 Restore the user FPCR +// 2.2 Return ans := Y * INV_L10. +// +// +// slog10: +// +// Step 0. If X < 0, create a NaN and raise the invalid operation +// flag. Otherwise, save FPCR in D1; set FpCR to default. +// Notes: Default means round-to-nearest mode, no floating-point +// traps, and precision control = double extended. +// +// Step 1. Call sLogN to obtain Y = log(X), the natural log of X. +// +// Step 2. Compute log_10(X) = log(X) * (1/log(10)). +// 2.1 Restore the user FPCR +// 2.2 Return ans := Y * INV_L10. +// +// +// sLog2d: +// +// Step 0. If X < 0, create a NaN and raise the invalid operation +// flag. Otherwise, save FPCR in D1; set FpCR to default. +// Notes: Default means round-to-nearest mode, no floating-point +// traps, and precision control = double extended. +// +// Step 1. Call slognd to obtain Y = log(X), the natural log of X. +// Notes: Even if X is denormalized, log(X) is always normalized. +// +// Step 2. Compute log_10(X) = log(X) * (1/log(2)). +// 2.1 Restore the user FPCR +// 2.2 Return ans := Y * INV_L2. +// +// +// sLog2: +// +// Step 0. If X < 0, create a NaN and raise the invalid operation +// flag. Otherwise, save FPCR in D1; set FpCR to default. +// Notes: Default means round-to-nearest mode, no floating-point +// traps, and precision control = double extended. +// +// Step 1. If X is not an integer power of two, i.e., X != 2^k, +// go to Step 3. +// +// Step 2. Return k. +// 2.1 Get integer k, X = 2^k. +// 2.2 Restore the user FPCR. +// 2.3 Return ans := convert-to-double-extended(k). +// +// Step 3. Call sLogN to obtain Y = log(X), the natural log of X. +// +// Step 4. Compute log_2(X) = log(X) * (1/log(2)). +// 4.1 Restore the user FPCR +// 4.2 Return ans := Y * INV_L2. +// + +// Copyright (C) Motorola, Inc. 1990 +// All Rights Reserved +// +// THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF MOTOROLA +// The copyright notice above does not evidence any +// actual or intended publication of such source code. + +//SLOG2 idnt 2,1 | Motorola 040 Floating Point Software Package + + |section 8 + + |xref t_frcinx + |xref t_operr + |xref slogn + |xref slognd + +INV_L10: .long 0x3FFD0000,0xDE5BD8A9,0x37287195,0x00000000 + +INV_L2: .long 0x3FFF0000,0xB8AA3B29,0x5C17F0BC,0x00000000 + + .global slog10d +slog10d: +//--entry point for Log10(X), X is denormalized + movel (%a0),%d0 + blt invalid + movel %d1,-(%sp) + clrl %d1 + bsr slognd // ...log(X), X denorm. + fmovel (%sp)+,%fpcr + fmulx INV_L10,%fp0 + bra t_frcinx + + .global slog10 +slog10: +//--entry point for Log10(X), X is normalized + + movel (%a0),%d0 + blt invalid + movel %d1,-(%sp) + clrl %d1 + bsr slogn // ...log(X), X normal. + fmovel (%sp)+,%fpcr + fmulx INV_L10,%fp0 + bra t_frcinx + + + .global slog2d +slog2d: +//--entry point for Log2(X), X is denormalized + + movel (%a0),%d0 + blt invalid + movel %d1,-(%sp) + clrl %d1 + bsr slognd // ...log(X), X denorm. + fmovel (%sp)+,%fpcr + fmulx INV_L2,%fp0 + bra t_frcinx + + .global slog2 +slog2: +//--entry point for Log2(X), X is normalized + movel (%a0),%d0 + blt invalid + + movel 8(%a0),%d0 + bnes continue // ...X is not 2^k + + movel 4(%a0),%d0 + andl #0x7FFFFFFF,%d0 + tstl %d0 + bnes continue + +//--X = 2^k. + movew (%a0),%d0 + andl #0x00007FFF,%d0 + subl #0x3FFF,%d0 + fmovel %d1,%fpcr + fmovel %d0,%fp0 + bra t_frcinx + +continue: + movel %d1,-(%sp) + clrl %d1 + bsr slogn // ...log(X), X normal. + fmovel (%sp)+,%fpcr + fmulx INV_L2,%fp0 + bra t_frcinx + +invalid: + bra t_operr + + |end -- cgit v1.2.3