ack/mach/powerpc/libem/aar4.s
George Koehler 26de4c1ab1 Add test for EM _rck_. Fix traps in PowerPC ncg.
The new test rck_e.e segfaults on PowerPC unless I make some changes.
The inline code for _rck_ was wrong because it didn't allow the trap
handler to return.  _sig_ forgot to push the old trap handler.

Move plat/linuxppc/libsys/trap.s to mach/powerpc/libem/trp.s and
rewrite it with simplified/extended mnemonics.  Remove .trap alias for
.trp procedure.  Add a missing `mtspr lr, r0` so we can return from
the trap handler.  Call write() and _exit() so trp.s works with both
linuxppc and osxppc.  Before, Mac OS X was wrongly using the trap.s
for Linux.

In powerpc/libem, simplify .aar4; teach .csa and .csb to raise the
trap if the default target is zero.

C programs don't need these changes.  You may relink your C programs
with the changed .csa and .csb, but C code doesn't raise the trap.
Modula-2 code can raise traps, so you may want to relink your Modula-2
programs with the changed libem, but you might keep your old .o files
from Modula-2.  You may need to recompile your Pascal programs (delete
old .o files from Pascal) because the Pascal compiler might use _rck_.
2017-12-24 22:37:52 -05:00

33 lines
829 B
ArmAsm

.sect .text
! Get address of element of bounds-checked array.
!
! Stack: ( array-adr index descriptor-adr -- element-adr )
! Sets r3 = size of element for .los4, .sts4
! Preserves r10 for .lar4, .sar4
.define .aar4
.aar4:
lwz r4, 0(sp) ! r4 = address of descriptor
lwz r5, 4(sp) ! r5 = index
lwz r6, 8(sp) ! r6 = address of array
lwz r0, 0(r4)
subf. r5, r0, r5 ! subtract lower bound from index
blt .trap_earray ! check lower bound
lwz r0, 4(r4)
cmplw r5, r0
bgt .trap_earray ! check upper bound
lwz r3, 8(r4) ! r3 = size of element
mullw r5, r5, r3 ! scale index by size
add r6, r6, r5
stw r6, 8(sp) ! push address of element
addi sp, sp, 8
blr
.trap_earray:
li r3, 0 ! EARRAY = 0 in h/em_abs.h
b .trp