+++ /dev/null
-// window-vectors.S - Register Window Overflow/Underflow Handlers
-// $Id: //depot/rel/Cottonwood/Xtensa/OS/xtos/window-vectors.S#3 $
-
-// Copyright (c) 1999-2010 Tensilica Inc.
-//
-// Permission is hereby granted, free of charge, to any person obtaining
-// a copy of this software and associated documentation files (the
-// "Software"), to deal in the Software without restriction, including
-// without limitation the rights to use, copy, modify, merge, publish,
-// distribute, sublicense, and/or sell copies of the Software, and to
-// permit persons to whom the Software is furnished to do so, subject to
-// the following conditions:
-//
-// The above copyright notice and this permission notice shall be included
-// in all copies or substantial portions of the Software.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
-// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
-// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
-// IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
-// CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
-// TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
-// SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
-
-#include <xtensa/coreasm.h>
-
-#if XCHAL_HAVE_WINDOWED && !defined(__XTENSA_CALL0_ABI__)
-
-# ifndef NO_SECTION_DIRECTIVES
-// Exports
-.global _WindowOverflow4
-.global _WindowUnderflow4
-.global _WindowOverflow8
-.global _WindowUnderflow8
-.global _WindowOverflow12
-.global _WindowUnderflow12
-
- // Note: the current window exception vectors do not generate any
- // literals. Hence the literal_prefix directive is not necessary.
- // Specifying it "just in case" creates an empty section (named
- // ".WindowVectors.literal") which can in some cases cause linking
- // problems (the linker scripts don't place it anywhere).
- // So leave it commented out:
- //
- //.begin literal_prefix .WindowVectors
-
- .section .WindowVectors.text, "ax"
-# endif
-
-
-//
-// GENERAL NOTES:
-//
-// These window exception handlers need not be modified.
-// They are specific to the windowed call ABI only.
-//
-// Underflow Handlers:
-//
-// The underflow handler for returning from call[i+1] to call[i]
-// must preserve all the registers from call[i+1]'s window.
-// In particular, a0 and a1 must be preserved because the RETW instruction
-// will be reexecuted (and may even underflow again if an intervening
-// exception has flushed call[i]'s registers).
-// Registers a2 and up may contain return values.
-//
-// The caller could also potentially assume that the callee's a0 and a1
-// (its own a4&a5 if call4, a8&a9 if call8, a12&a13 if call12)
-// are correct for whatever reason (not a clean thing to do in general,
-// but if it's possible, unless the ABI explicitly prohibits it,
-// it will eventually be done :) -- whether the the ABI needs to
-// prohibit this is a different question).
-//
-// Timing of Handlers:
-//
-// Here is an overview of the overhead of taking a window exception,
-// ie. the number of additional cycles taken relative to case where
-// an exception is not taken.
-// NOTE: these numbers do not take into account any cache misses,
-// write buffer stalls, or other external stalls, if they occur.
-// The totals consist of 5 cycles to enter the handler (or 6 or 7
-// for optional longer pipelines in Xtensa LX), the number of instructions
-// and interlocks (2nd and 3rd columns below), and 2 cycles jump delay
-// on return (3 cycles for optional longer I-side pipeline in Xtensa LX):
-//
-// Instruction+bubbles Totals (5-stage)
-// XEA1 XEA2 XEA1 XEA2
-// Overflow-4 7 5 14 12
-// Overflow-8 14 10 21 17
-// Overflow-12 18 14 25 21
-// Underflow-4 6 5 13 12
-// Underflow-8 14 10 21 17
-// Underflow-12 18 14 25 21
-//
-// Underflow-8 15 12 25 22 (7-stage; could be made 1 less)
-// Underflow-12 19 16 29 26 (7-stage; could be made 1 less)
-
-#ifndef WINDOW_BASE_VECOFS
-#define WINDOW_BASE_VECOFS XCHAL_WINDOW_OF4_VECOFS
-#endif
-
-
-// 4-Register Window Overflow Vector (Handler)
-//
-// Invoked if a call[i] referenced a register (a4-a15)
-// that contains data from ancestor call[j];
-// call[j] had done a call4 to call[j+1].
-// On entry here:
-// window rotated to call[j] start point;
-// a0-a3 are registers to be saved;
-// a4-a15 must be preserved;
-// a5 is call[j+1]'s stack pointer.
-
- .org XCHAL_WINDOW_OF4_VECOFS - WINDOW_BASE_VECOFS
-_WindowOverflow4:
-#if XCHAL_HAVE_XEA1
- addi a5, a5, -16 // to make store offsets positive
- s32i a0, a5, 0 // save a0 to call[j+1]'s stack frame
- s32i a1, a5, 4 // save a1 to call[j+1]'s stack frame
- s32i a2, a5, 8 // save a2 to call[j+1]'s stack frame
- s32i a3, a5, 12 // save a3 to call[j+1]'s stack frame
- addi a5, a5, 16 // restore a5
-#else
- s32e a0, a5, -16 // save a0 to call[j+1]'s stack frame
- s32e a1, a5, -12 // save a1 to call[j+1]'s stack frame
- s32e a2, a5, -8 // save a2 to call[j+1]'s stack frame
- s32e a3, a5, -4 // save a3 to call[j+1]'s stack frame
-#endif
- rfwo // rotates back to call[i] position
-
- .size _WindowOverflow4, . - _WindowOverflow4
-
-
-// 4-Register Window Underflow Vector (Handler)
-//
-// Invoked by RETW returning from call[i+1] to call[i]
-// where call[i]'s registers must be reloaded (not live in ARs);
-// call[i] had done a call4 to call[i+1].
-// On entry here:
-// window rotated to call[i] start point;
-// a0-a3 are undefined, must be reloaded with call[i].reg[0..3];
-// a4-a15 must be preserved (they are call[i+1].reg[0..11]);
-// a5 is call[i+1]'s stack pointer.
-
- .org XCHAL_WINDOW_UF4_VECOFS - WINDOW_BASE_VECOFS
-_WindowUnderflow4:
-#if XCHAL_HAVE_XEA1
- addi a3, a5, -16 // to make load offsets positive
- l32i a0, a3, 0 // restore a0 from call[i+1]'s stack frame
- l32i a1, a3, 4 // restore a1 from call[i+1]'s stack frame
- l32i a2, a3, 8 // restore a2 from call[i+1]'s stack frame
- l32i a3, a3, 12 // restore a3 from call[i+1]'s stack frame
-#else
- l32e a0, a5, -16 // restore a0 from call[i+1]'s stack frame
- l32e a1, a5, -12 // restore a1 from call[i+1]'s stack frame
- l32e a2, a5, -8 // restore a2 from call[i+1]'s stack frame
- l32e a3, a5, -4 // restore a3 from call[i+1]'s stack frame
-#endif
- rfwu
-
- .size _WindowUnderflow4, . - _WindowUnderflow4
-
-
-// 8-Register Window Overflow Vector (Handler)
-//
-// Invoked if a call[i] referenced a register (a4-a15)
-// that contains data from ancestor call[j];
-// call[j] had done a call8 to call[j+1].
-// On entry here:
-// window rotated to call[j] start point;
-// a0-a7 are registers to be saved;
-// a8-a15 must be preserved;
-// a9 is call[j+1]'s stack pointer.
-
- .org XCHAL_WINDOW_OF8_VECOFS - WINDOW_BASE_VECOFS
-_WindowOverflow8:
-#if XCHAL_HAVE_XEA1
- addi a9, a9, -16 // to make store offsets positive
- s32i a0, a9, 0 // save a0 to call[j+1]'s stack frame
- addi a0, a1, -16 // a0 <- call[j-1]'s sp
- s32i a1, a9, 4 // save a1 to call[j+1]'s stack frame
- l32i a0, a0, 4 // (used to find end of call[j]'s frame)
- s32i a2, a9, 8 // save a2 to call[j+1]'s stack frame
- s32i a3, a9, 12 // save a3 to call[j+1]'s stack frame
- addi a9, a9, 16 // restore a9
- addi a0, a0, -32 // to make load offsets positive
- s32i a4, a0, 0 // save a4 to call[j]'s stack frame
- s32i a5, a0, 4 // save a5 to call[j]'s stack frame
- s32i a6, a0, 8 // save a6 to call[j]'s stack frame
- s32i a7, a0, 12 // save a7 to call[j]'s stack frame
-#else
- s32e a0, a9, -16 // save a0 to call[j+1]'s stack frame
- l32e a0, a1, -12 // a0 <- call[j-1]'s sp (used to find end of call[j]'s frame)
- s32e a1, a9, -12 // save a1 to call[j+1]'s stack frame
- s32e a2, a9, -8 // save a2 to call[j+1]'s stack frame
- s32e a3, a9, -4 // save a3 to call[j+1]'s stack frame
- s32e a4, a0, -32 // save a4 to call[j]'s stack frame
- s32e a5, a0, -28 // save a5 to call[j]'s stack frame
- s32e a6, a0, -24 // save a6 to call[j]'s stack frame
- s32e a7, a0, -20 // save a7 to call[j]'s stack frame
-#endif
- rfwo // rotates back to call[i] position
-
- .size _WindowOverflow8, . - _WindowOverflow8
-
-
-// 8-Register Window Underflow Vector (Handler)
-//
-// Invoked by RETW returning from call[i+1] to call[i]
-// where call[i]'s registers must be reloaded (not live in ARs);
-// call[i] had done a call8 to call[i+1].
-// On entry here:
-// window rotated to call[i] start point;
-// a0-a7 are undefined, must be reloaded with call[i].reg[0..7];
-// a8-a15 must be preserved (they are call[i+1].reg[0..7]);
-// a9 is call[i+1]'s stack pointer.
-
- .org XCHAL_WINDOW_UF8_VECOFS - WINDOW_BASE_VECOFS
-_WindowUnderflow8:
-#if XCHAL_HAVE_XEA1
- addi a9, a9, -16 // to make load offsets positive
- l32i a0, a9, 0 // restore a0 from call[i+1]'s stack frame
- l32i a1, a9, 4 // restore a1 from call[i+1]'s stack frame
- l32i a2, a9, 8 // restore a2 from call[i+1]'s stack frame
- addi a7, a1, -16 // a7 <- call[i-1]'s sp
- l32i a7, a7, 4 // (used to find end of call[i]'s frame)
- l32i a3, a9, 12 // restore a3 from call[i+1]'s stack frame
- addi a9, a9, 16 // restore a9
- addi a7, a7, -32 // to make load offsets positive
- l32i a4, a7, 0 // restore a4 from call[i]'s stack frame
- l32i a5, a7, 4 // restore a5 from call[i]'s stack frame
- l32i a6, a7, 8 // restore a6 from call[i]'s stack frame
- l32i a7, a7, 12 // restore a7 from call[i]'s stack frame
-#else
- l32e a0, a9, -16 // restore a0 from call[i+1]'s stack frame
- l32e a1, a9, -12 // restore a1 from call[i+1]'s stack frame
- l32e a2, a9, -8 // restore a2 from call[i+1]'s stack frame
- l32e a7, a1, -12 // a7 <- call[i-1]'s sp (used to find end of call[i]'s frame)
- l32e a3, a9, -4 // restore a3 from call[i+1]'s stack frame
- l32e a4, a7, -32 // restore a4 from call[i]'s stack frame
- l32e a5, a7, -28 // restore a5 from call[i]'s stack frame
- l32e a6, a7, -24 // restore a6 from call[i]'s stack frame
- l32e a7, a7, -20 // restore a7 from call[i]'s stack frame
-#endif
- rfwu
-
- .size _WindowUnderflow8, . - _WindowUnderflow8
-
-
-// 12-Register Window Overflow Vector (Handler)
-//
-// Invoked if a call[i] referenced a register (a4-a15)
-// that contains data from ancestor call[j];
-// call[j] had done a call12 to call[j+1].
-// On entry here:
-// window rotated to call[j] start point;
-// a0-a11 are registers to be saved;
-// a12-a15 must be preserved;
-// a13 is call[j+1]'s stack pointer.
-
- .org XCHAL_WINDOW_OF12_VECOFS - WINDOW_BASE_VECOFS
-_WindowOverflow12:
-#if XCHAL_HAVE_XEA1
- addi a13, a13, -16 // to make store offsets positive
- s32i a0, a13, 0 // save a0 to call[j+1]'s stack frame
- addi a0, a1, -16 // a0 <- call[j-1]'s sp
- s32i a1, a13, 4 // save a1 to call[j+1]'s stack frame
- l32i a0, a0, 4 // (used to find end of call[j]'s frame)
- s32i a2, a13, 8 // save a2 to call[j+1]'s stack frame
- s32i a3, a13, 12 // save a3 to call[j+1]'s stack frame
- addi a13, a13, 16 // restore a13
- addi a0, a0, -48 // to make load offsets positive
- s32i a4, a0, 0 // save a4 to end of call[j]'s stack frame
- s32i a5, a0, 4 // save a5 to end of call[j]'s stack frame
- s32i a6, a0, 8 // save a6 to end of call[j]'s stack frame
- s32i a7, a0, 12 // save a7 to end of call[j]'s stack frame
- s32i a8, a0, 16 // save a8 to end of call[j]'s stack frame
- s32i a9, a0, 20 // save a9 to end of call[j]'s stack frame
- s32i a10, a0, 24 // save a10 to end of call[j]'s stack frame
- s32i a11, a0, 28 // save a11 to end of call[j]'s stack frame
-#else
- s32e a0, a13, -16 // save a0 to call[j+1]'s stack frame
- l32e a0, a1, -12 // a0 <- call[j-1]'s sp (used to find end of call[j]'s frame)
- s32e a1, a13, -12 // save a1 to call[j+1]'s stack frame
- s32e a2, a13, -8 // save a2 to call[j+1]'s stack frame
- s32e a3, a13, -4 // save a3 to call[j+1]'s stack frame
- s32e a4, a0, -48 // save a4 to end of call[j]'s stack frame
- s32e a5, a0, -44 // save a5 to end of call[j]'s stack frame
- s32e a6, a0, -40 // save a6 to end of call[j]'s stack frame
- s32e a7, a0, -36 // save a7 to end of call[j]'s stack frame
- s32e a8, a0, -32 // save a8 to end of call[j]'s stack frame
- s32e a9, a0, -28 // save a9 to end of call[j]'s stack frame
- s32e a10, a0, -24 // save a10 to end of call[j]'s stack frame
- s32e a11, a0, -20 // save a11 to end of call[j]'s stack frame
-#endif
- rfwo // rotates back to call[i] position
-
- .size _WindowOverflow12, . - _WindowOverflow12
-
-
-// 12-Register Window Underflow Vector (Handler)
-//
-// Invoked by RETW returning from call[i+1] to call[i]
-// where call[i]'s registers must be reloaded (not live in ARs);
-// call[i] had done a call12 to call[i+1].
-// On entry here:
-// window rotated to call[i] start point;
-// a0-a11 are undefined, must be reloaded with call[i].reg[0..11];
-// a12-a15 must be preserved (they are call[i+1].reg[0..3]);
-// a13 is call[i+1]'s stack pointer.
-
- .org XCHAL_WINDOW_UF12_VECOFS - WINDOW_BASE_VECOFS
-_WindowUnderflow12:
-#if XCHAL_HAVE_XEA1
- addi a13, a13, -16 // to make load offsets positive
- l32i a0, a13, 0 // restore a0 from call[i+1]'s stack frame
- l32i a1, a13, 4 // restore a1 from call[i+1]'s stack frame
- l32i a2, a13, 8 // restore a2 from call[i+1]'s stack frame
- addi a11, a1, -16 // a11 <- call[i-1]'s sp
- l32i a11, a11, 4 // (used to find end of call[i]'s frame)
- l32i a3, a13, 12 // restore a3 from call[i+1]'s stack frame
- addi a13, a13, 16 // restore a13
- addi a11, a11, -48 // to make load offsets positive
- l32i a4, a11, 0 // restore a4 from end of call[i]'s stack frame
- l32i a5, a11, 4 // restore a5 from end of call[i]'s stack frame
- l32i a6, a11, 8 // restore a6 from end of call[i]'s stack frame
- l32i a7, a11, 12 // restore a7 from end of call[i]'s stack frame
- l32i a8, a11, 16 // restore a8 from end of call[i]'s stack frame
- l32i a9, a11, 20 // restore a9 from end of call[i]'s stack frame
- l32i a10, a11, 24 // restore a10 from end of call[i]'s stack frame
- l32i a11, a11, 28 // restore a11 from end of call[i]'s stack frame
-#else
- l32e a0, a13, -16 // restore a0 from call[i+1]'s stack frame
- l32e a1, a13, -12 // restore a1 from call[i+1]'s stack frame
- l32e a2, a13, -8 // restore a2 from call[i+1]'s stack frame
- l32e a11, a1, -12 // a11 <- call[i-1]'s sp (used to find end of call[i]'s frame)
- l32e a3, a13, -4 // restore a3 from call[i+1]'s stack frame
- l32e a4, a11, -48 // restore a4 from end of call[i]'s stack frame
- l32e a5, a11, -44 // restore a5 from end of call[i]'s stack frame
- l32e a6, a11, -40 // restore a6 from end of call[i]'s stack frame
- l32e a7, a11, -36 // restore a7 from end of call[i]'s stack frame
- l32e a8, a11, -32 // restore a8 from end of call[i]'s stack frame
- l32e a9, a11, -28 // restore a9 from end of call[i]'s stack frame
- l32e a10, a11, -24 // restore a10 from end of call[i]'s stack frame
- l32e a11, a11, -20 // restore a11 from end of call[i]'s stack frame
-#endif
- rfwu
-
- .size _WindowUnderflow12, . - _WindowUnderflow12
-
-
-# ifndef NO_SECTION_DIRECTIVES
- //.end literal_prefix
- .text
-# endif
-
-
-#endif /* XCHAL_HAVE_WINDOWED && !defined(__XTENSA_CALL0_ABI__) */
-
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