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o Fix _longjmp() to return 1 when the return value is given as 0.

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o  Remove the unwanted smartness in _longjmp() where it compares
   the current ar.bspstore with the saved ar.bspstore and restores
   ar.rnat based on it. This either avoids saving ar.rnat in the
   jmp_buf or is the consequence of not saving ar.rnat. All this
   complexity breaks libc_r where we use longjmp() to switch to
   different threads and the current ar.bspstore has no relation
   to the saved ar.bspstore. Thus: we save ar.rnat in setjmp()
   and simply restore ar.bspstore and ar.rnat in longjmp().

This code needs a cleanup.
This commit is contained in:
Marcel Moolenaar 2002-11-14 06:40:23 +00:00
parent ca161eb6e9
commit 122dd01309
1 changed files with 25 additions and 52 deletions
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75
lib/libc/ia64/gen/_setjmp.S
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@ -95,24 +95,30 @@ ENTRY(_setjmp, 1)
//
// save preserved general registers & NaT's
//
.mem.offset 0,0
st8.spill [r11] = r4, J_R6-J_R4
;;
.mem.offset 8,0
st8.spill [r10] = r5, J_R7-J_R5
;;
.mem.offset 16,0
st8.spill [r11] = r6, J_SP-J_R6
;;
.mem.offset 24,0
st8.spill [r10] = r7, J_F3-J_R7
;;
st8.spill [r11] = sp, J_F2-J_SP
mov r16 = ar.rsc
;;
//
// save spilled Unat and pfs registers
//
mov r2 = ar.unat // save Unat register after spill
mov ar.rsc = r0
;;
st8 [r32] = r2, J_PFS-J_NATS // save unat for spilled regs
mov r17 = ar.rnat
;;
st8 [r32] = r15 // save pfs
st8 [r32] = r15, J_RNAT-J_PFS // save pfs
mov ar.rsc = r16
//
// save floating registers
//
@ -145,6 +151,8 @@ ENTRY(_setjmp, 1)
;;
stf.spill [r11] = f30, J_FPSR-J_F30
stf.spill [r10] = f31, J_B0-J_F31 // size of f31 + fpsr
;;
st8 [r32] = r17
//
// save FPSR register & branch registers
//
@ -192,67 +200,32 @@ END(_setjmp)
WEAK_ALIAS(_longjmp,___longjmp)
ENTRY(___longjmp, 2)
//
// caching the return value as we do invala in the end
//
mov r8 = r33 // return value
//
// get immediate context
//
mov r14 = ar.rsc // get user RSC conf
mov r8 = r33 // return value
add r10 = J_PFS, r32 // get address of pfs
;;
mov ar.rsc = r0
add r11 = J_NATS, r32
add r17 = J_RNAT, r32
;;
ld8 r15 = [r10], J_BSP-J_PFS // get pfs
ld8 r2 = [r11], J_LC-J_NATS // get unat for spilled regs
mov r31 = r32
;;
loadrs
mov ar.unat = r2
cmp.eq p6,p0=0,r8 // Return value 0?
;;
ld8 r16 = [r10], J_PREDS-J_BSP // get backing store pointer
mov ar.rsc = r0 // put RSE in enforced lazy
ld8 r17 = [r17] // ar.rnat
mov ar.pfs = r15
;;
//
// while returning from longjmp the BSPSTORE and BSP needs to be
// same and discard all the registers allocated after we did
// setjmp. Also, we need to generate the RNAT register since we
// did not flushed the RSE on setjmp.
//
mov r17 = ar.bspstore // get current BSPSTORE
mov ar.bspstore = r16
(p6) add r8 = 1, r0
;;
cmp.ltu p6,p7 = r17, r16 // is it less than BSP of
(p6) br.spnt.few .flush_rse
mov r19 = ar.rnat // get current RNAT
;;
loadrs // invalidate dirty regs
br.sptk.many .restore_rnat // restore RNAT
.flush_rse:
flushrs
;;
mov r19 = ar.rnat // get current RNAT
mov r17 = r16 // current BSPSTORE
;;
.restore_rnat:
//
// check if RNAT is saved between saved BSP and curr BSPSTORE
//
mov r18 = 0x3f
;;
dep r18 = r18,r16,3,6 // get RNAT address
;;
cmp.ltu p8,p9 = r18, r17 // RNAT saved on RSE
;;
(p8) ld8 r19 = [r18] // get RNAT from RSE
;;
mov ar.bspstore = r16 // set new BSPSTORE
;;
mov ar.rnat = r19 // restore RNAT
mov ar.rnat = r17
mov ar.rsc = r14 // restore RSC conf
ld8 r3 = [r11], J_R4-J_LC // get lc register
ld8 r2 = [r10], J_R5-J_PREDS // get predicates
;;
@ -316,12 +289,12 @@ ENTRY(___longjmp, 2)
mov b1 = r2
mov b2 = r3
ld8 r2 = [r10], J_B5-J_B3
ld8 r3 = [r11]
ld8 r3 = [r11],
;;
mov b3 = r2
mov b4 = r3
ld8 r2 = [r10]
ld8 r21 = [r32] // get user unat
ld8 r21 = [r31] // get user unat
;;
mov b5 = r2
mov ar.unat = r21