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Diffstat (limited to 'private/crt32/misc/alpha/setjmpex.s')
-rw-r--r-- | private/crt32/misc/alpha/setjmpex.s | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/private/crt32/misc/alpha/setjmpex.s b/private/crt32/misc/alpha/setjmpex.s new file mode 100644 index 000000000..3f39baa7b --- /dev/null +++ b/private/crt32/misc/alpha/setjmpex.s @@ -0,0 +1,147 @@ +// TITLE("Set Jump Extended") +//++ +// +// Copyright (c) 1993 Microsoft Corporation +// Copyright (c) 1993 Digital Equipment Corporation +// +// Module Name: +// +// setjmpex.s +// +// Abstract: +// +// This module implements the Alpha acc compiler specific routine to +// provide SAFE handling of setjmp/longjmp with respect to structured +// exception handling. +// +// Author: +// +// David N. Cutler (davec) 2-Apr-1993 +// +// Environment: +// +// Any mode. +// +// Revision History: +// +// Thomas Van Baak (tvb) 22-Apr-1993 +// +// Adapted for Alpha AXP. +// +//-- + +#include "ksalpha.h" + +// +// Define variable that will cause setjmp/longjmp to be safe with respect +// to structured exception handling. +// + + .globl _setjmpexused + .data +_setjmpexused: + .long _setjmpex // set address of safe setjmp routine + + SBTTL("Set Jump Extended") +//++ +// +// int +// _setjmpex ( +// IN jmp_buf JumpBuffer +// ) +// +// Routine Description: +// +// This function implements a safe setjmp. +// +// Arguments: +// +// JumpBuffer (a0) - Supplies the address of a jump buffer to store the +// jump information. +// +// Return Value: +// +// A value of zero is returned. +// +//-- + + .struct 0 +SjRa: .space 8 // saved return address +SjS0: .space 8 // saved integer register s0 +SjFl: .space 8 // InFunction flag variable +SjEf: .space 8 // EstablisherFrame(s) structure +SjCx: .space ContextFrameLength // context frame +SetjmpFrameLength: + + NESTED_ENTRY(_setjmpex, SetjmpFrameLength, zero) + + lda sp, -SetjmpFrameLength(sp) // allocate stack frame + stq ra, SjRa(sp) // save return address + stq s0, SjS0(sp) // save integer register s0 + + PROLOGUE_END + +// +// Save the nonvolatile machine state. +// + + lda t0, SjCx(sp) // address of context record + + stt f2, CxFltF2(t0) // save floating registers f2 - f9 + stt f3, CxFltF3(t0) // + stt f4, CxFltF4(t0) // + stt f5, CxFltF5(t0) // + stt f6, CxFltF6(t0) // + stt f7, CxFltF7(t0) // + stt f8, CxFltF8(t0) // + stt f9, CxFltF9(t0) // + + stq s0, CxIntS0(t0) // save integer registers s0 - fp/s6 + stq s1, CxIntS1(t0) // + stq s2, CxIntS2(t0) // + stq s3, CxIntS3(t0) // + stq s4, CxIntS4(t0) // + stq s5, CxIntS5(t0) // + stq fp, CxIntFp(t0) // + stq gp, CxIntGp(t0) // save integer register gp + + lda v0, SetjmpFrameLength(sp) // compute stack pointer address + stq v0, CxIntSp(t0) // save stack pointer + stq ra, CxIntRa(t0) // save return address + stq ra, CxFir(t0) // save continuation address + + ldil t1, 2 // get acc safe setjmp flag + stl t1, JbType(a0) // set jump buffer context type + stl ra, JbPc(a0) // save target instruction address + mov a0, s0 // preserve jump buffer address + +// +// Perform unwind to determine the virtual frame pointer of the caller. +// + + subl ra, 4, a0 // compute control PC address + bsr RtlLookupFunctionEntry // lookup function table address + + ldq a0, SjRa(sp) // get return address + subl a0, 4, a0 // compute control PC address + mov v0, a1 // set address of function entry + lda a2, SjCx(sp) // address of context record + lda a3, SjFl(sp) // set address of in function variable + lda a4, SjEf(sp) // set frame pointers address + mov zero, a5 // set context pointer array address + bsr RtlVirtualUnwind // compute virtual frame pointer value + +// +// Set return value, restore registers, deallocate stack frame, and return. +// + + ldl t0, SjEf(sp) // get virtual frame pointer + stl t0, JbFp(s0) // save virtual frame pointer address + mov zero, v0 // set return value + + ldq s0, SjS0(sp) // restore integer register s0 + ldq ra, SjRa(sp) // restore return address + lda sp, SetjmpFrameLength(sp) // deallocate stack frame + ret zero, (ra) // return + + .end _setjmpex |