diff options
Diffstat (limited to 'ext/systemc/src/sysc/qt/md/i386.s')
| -rw-r--r-- | ext/systemc/src/sysc/qt/md/i386.s | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/ext/systemc/src/sysc/qt/md/i386.s b/ext/systemc/src/sysc/qt/md/i386.s new file mode 100644 index 000000000..b5806cd27 --- /dev/null +++ b/ext/systemc/src/sysc/qt/md/i386.s @@ -0,0 +1,119 @@ +/* i386.s -- assembly support. */ + +/* +// QuickThreads -- Threads-building toolkit. +// Copyright (c) 1993 by David Keppel +// +// Permission to use, copy, modify and distribute this software and +// its documentation for any purpose and without fee is hereby +// granted, provided that the above copyright notice and this notice +// appear in all copies. This software is provided as a +// proof-of-concept and for demonstration purposes; there is no +// representation about the suitability of this software for any +// purpose. */ + +/* NOTE: double-labeled `_name' and `name' for System V compatability. */ +/* NOTE: Mixed C/C++-style comments used. Sorry! */ + +/* Callee-save: %esi, %edi, %ebx, %ebp +// Caller-save: %eax, %ecx +// Can't tell: %edx (seems to work w/o saving it.) +// +// Assignment: +// +// See ``i386.h'' for the somewhat unconventional stack layout. */ + + + .text + .align 2 + + .globl _qt_abort + .globl qt_abort + .globl _qt_block + .globl qt_block + .globl _qt_blocki + .globl qt_blocki + .globl _qt_align + .globl qt_align + +/* These all have the type signature +// +// void *blocking (helper, arg0, arg1, new) +// +// On procedure entry, the helper is at 4(sp), args at 8(sp) and +// 12(sp) and the new thread's sp at 16(sp). It *appears* that the +// calling convention for the 8X86 requires the caller to save all +// floating-point registers, this makes our life easy. */ + +/* Halt the currently-running thread. Save it's callee-save regs on +// to the stack, 32 bytes. Switch to the new stack (next == 16+32(sp)) +// and call the user function (f == 4+32(sp) with arguments: old sp +// arg1 (8+32(sp)) and arg2 (12+32(sp)). When the user function is +// done, restore the new thread's state and return. +// +// `qt_abort' is (currently) an alias for `qt_block' because most of +// the work is shared. We could save the insns up to `qt_common' by +// replicating, but w/o replicating we need an inital subtract (to +// offset the stack as if it had been a qt_block) and then a jump +// to qt_common. For the cost of a jump, we might as well just do +// all the work. +// +// The helper function (4(sp)) can return a void* that is returned +// by the call to `qt_blockk{,i}'. Since we don't touch %eax in +// between, we get that ``for free''. */ + +_qt_abort: +qt_abort: +_qt_block: +qt_block: +_qt_blocki: +qt_blocki: + pushl %ebp /* Save callee-save, sp-=4. */ + pushl %esi /* Save callee-save, sp-=4. */ + pushl %edi /* Save callee-save, sp-=4. */ + pushl %ebx /* Save callee-save, sp-=4. */ + movl %esp, %eax /* Remember old stack pointer. */ + +qt_common: + movl 32(%esp), %esp /* Move to new thread. */ + pushl 28(%eax) /* Push arg 2. */ + pushl 24(%eax) /* Push arg 1. */ + pushl %eax /* Push arg 0. */ + movl 20(%eax), %ebx /* Get function to call. */ + call *%ebx /* Call f. */ + addl $12, %esp /* Pop args. */ + + popl %ebx /* Restore callee-save, sp+=4. */ + popl %edi /* Restore callee-save, sp+=4. */ + popl %esi /* Restore callee-save, sp+=4. */ + popl %ebp /* Restore callee-save, sp+=4. */ +_qt_align: +qt_align: + ret /* Resume the stopped function. */ + + .globl _qt_tramp + .globl qt_tramp +_qt_tramp: +qt_tramp: + movl 12(%esp), %eax /* Load 'qt_error' address */ + sub $4, %esp /* Align stack pointer to 16-byte boundary */ + jmp *%eax /* call 'qt_error' */ + hlt /* 'qt_error' never returns */ + +/* Start a varargs thread. */ + + .globl _qt_vstart + .globl qt_vstart +_qt_vstart: +qt_vstart: + pushl %edi /* Push `pt' arg to `startup'. */ + call *%ebp /* Call `startup'. */ + popl %eax /* Clean up the stack. */ + + call *%ebx /* Call the user's function. */ + + pushl %eax /* Push return from user's. */ + pushl %edi /* Push `pt' arg to `cleanup'. */ + call *%esi /* Call `cleanup'. */ + + hlt /* `cleanup' never returns. */ |