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Diffstat (limited to 'ext/systemc/src/sysc/qt/md/mips.s')
| -rw-r--r-- | ext/systemc/src/sysc/qt/md/mips.s | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/ext/systemc/src/sysc/qt/md/mips.s b/ext/systemc/src/sysc/qt/md/mips.s new file mode 100644 index 000000000..b074b98dc --- /dev/null +++ b/ext/systemc/src/sysc/qt/md/mips.s @@ -0,0 +1,164 @@ +/* mips.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. + */ + +/* Callee-save $16-$23, $30-$31. + * + * On startup, restore regs so retpc === call to a function to start. + * We're going to call a function ($4) from within this routine. + * We're passing 3 args, therefore need to allocate 12 extra bytes on + * the stack for a save area. The start routine needs a like 16-byte + * save area. Must be doubleword aligned (_mips r3000 risc + * architecture_, gerry kane, pg d-23). + */ + + .globl qt_block + .globl qt_blocki + .globl qt_abort + .globl qt_start + .globl qt_vstart + + /* + ** $4: ptr to function to call once curr is suspended + ** and control is on $7's stack. + ** $5: 1'th arg to $4. + ** $6: 2'th arg to $4 + ** $7: sp of thread to suspend. + ** + ** Totally gross hack: The MIPS calling convention reserves + ** 4 words on the stack for a0..a3. This routine "ought" to + ** allocate space for callee-save registers plus 4 words for + ** the helper function, but instead we use the 4 words + ** provided by the function that called us (we don't need to + ** save our argument registers). So what *appears* to be + ** allocating only 40 bytes is actually allocating 56, by + ** using the caller's 16 bytes. + ** + ** The helper routine returns a value that is passed on as the + ** return value from the blocking routine. Since we don't + ** touch $2 between the helper's return and the end of + ** function, we get this behavior for free. + */ +qt_blocki: + sub $sp,$sp,40 /* Allocate reg save space. */ + sw $16, 0+16($sp) + sw $17, 4+16($sp) + sw $18, 8+16($sp) + sw $19,12+16($sp) + sw $20,16+16($sp) + sw $21,20+16($sp) + sw $22,24+16($sp) + sw $23,28+16($sp) + sw $30,32+16($sp) + sw $31,36+16($sp) + add $2, $sp,$0 /* $2 <= old sp to pass to func@$4. */ +qt_abort: + add $sp, $7,$0 /* $sp <= new sp. */ + .set noreorder + jal $31,$4 /* Call helper func@$4 . */ + add $4, $2,$0 /* $a0 <= pass old sp as a parameter. */ + .set reorder + lw $31,36+16($sp) /* Restore callee-save regs... */ + lw $30,32+16($sp) + lw $23,28+16($sp) + lw $22,24+16($sp) + lw $21,20+16($sp) + lw $20,16+16($sp) + lw $19,12+16($sp) + lw $18, 8+16($sp) + lw $17, 4+16($sp) + lw $16, 0+16($sp) /* Restore callee-save */ + + add $sp,$sp,40 /* Deallocate reg save space. */ + j $31 /* Return to caller. */ + + /* + ** Non-varargs thread startup. + ** Note: originally, 56 bytes were allocated on the stack. + ** The thread restore routine (_blocki/_abort) removed 40 + ** of them, which means there is still 16 bytes for the + ** argument area required by the MIPS calling convention. + */ +qt_start: + add $4, $16,$0 /* Load up user function pu. */ + add $5, $17,$0 /* ... user function pt. */ + add $6, $18,$0 /* ... user function userf. */ + jal $31,$19 /* Call `only'. */ + j qt_error + + + /* + ** Save calle-save floating-point regs $f20-$f30 + ** See comment in `qt_block' about calling conventinos and + ** reserved space. Use the same trick here, but here we + ** actually have to allocate all the bytes since we have to + ** leave 4 words leftover for `qt_blocki'. + ** + ** Return value from `qt_block' is the same as the return from + ** `qt_blocki'. We get that for free since we don't touch $2 + ** between the return from `qt_blocki' and the return from + ** `qt_block'. + */ +qt_block: + sub $sp, $sp,56 /* 6 8-byte regs, saved ret pc, aligned. */ + swc1 $f20, 0+16($sp) + swc1 $f22, 8+16($sp) + swc1 $f24, 16+16($sp) + swc1 $f26, 24+16($sp) + swc1 $f28, 32+16($sp) + swc1 $f30, 40+16($sp) + sw $31, 48+16($sp) + jal qt_blocki + lwc1 $f20, 0+16($sp) + lwc1 $f22, 8+16($sp) + lwc1 $f24, 16+16($sp) + lwc1 $f26, 24+16($sp) + lwc1 $f28, 32+16($sp) + lwc1 $f30, 40+16($sp) + lw $31, 48+16($sp) + add $sp, $sp,56 + j $31 + + + /* + ** First, call `startup' with the `pt' argument. + ** + ** Next, call the user's function with all arguments. + ** Note that we don't know whether args were passed in + ** integer regs, fp regs, or on the stack (See Gerry Kane + ** "MIPS R2000 RISC Architecture" pg D-22), so we reload + ** all the registers, possibly with garbage arguments. + ** + ** Finally, call `cleanup' with the `pt' argument and with + ** the return value from the user's function. It is an error + ** for `cleanup' to return. + */ +qt_vstart: + add $4, $17,$0 /* `pt' is arg0 to `startup'. */ + jal $31, $18 /* Call `startup'. */ + + add $sp, $sp,16 /* Free extra save space. */ + lw $4, 0($sp) /* Load up args. */ + lw $5, 4($sp) + lw $6, 8($sp) + lw $7, 12($sp) + lwc1 $f12, 0($sp) /* Load up fp args. */ + lwc1 $f14, 8($sp) + jal $31,$19 /* Call `userf'. */ + + add $4, $17,$0 /* `pt' is arg0 to `cleanup'. */ + add $5, $2,$0 /* Ret. val is arg1 to `cleanup'. */ + jal $31, $16 /* Call `cleanup'. */ + + j qt_error |