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tcg: forbid ld/st function to modify globals

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Mapping a memory address using a global and accessing it through
ld/st operations is currently broken. As it doesn't make any sense
to do that performance wise, let's forbid that.

Update the TCG documentation, and remove partial support for that.

Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
This commit is contained in:
Aurelien Jarno 2012-10-09 21:53:08 +02:00
parent 344028ba0f
commit b202d41ee7
2 changed files with 10 additions and 7 deletions
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3
tcg/README
View File

@ -349,6 +349,9 @@ st32_i64 t0, t1, offset
write(t0, t1 + offset)
Write 8, 16, 32 or 64 bits to host memory.
All this opcodes assume that the pointed host memory doesn't correspond
to a global. In the latter case the behaviour is unpredictable.
********* 64-bit target on 32-bit host support
The following opcodes are internal to TCG. Thus they are to be implemented by

14
tcg/tcg-opc.h
View File

@ -57,9 +57,9 @@ DEF(ld8s_i32, 1, 1, 1, 0)
DEF(ld16u_i32, 1, 1, 1, 0)
DEF(ld16s_i32, 1, 1, 1, 0)
DEF(ld_i32, 1, 1, 1, 0)
DEF(st8_i32, 0, 2, 1, TCG_OPF_SIDE_EFFECTS)
DEF(st16_i32, 0, 2, 1, TCG_OPF_SIDE_EFFECTS)
DEF(st_i32, 0, 2, 1, TCG_OPF_SIDE_EFFECTS)
DEF(st8_i32, 0, 2, 1, 0)
DEF(st16_i32, 0, 2, 1, 0)
DEF(st_i32, 0, 2, 1, 0)
/* arith */
DEF(add_i32, 1, 2, 0, 0)
DEF(sub_i32, 1, 2, 0, 0)
@ -115,10 +115,10 @@ DEF(ld16s_i64, 1, 1, 1, IMPL64)
DEF(ld32u_i64, 1, 1, 1, IMPL64)
DEF(ld32s_i64, 1, 1, 1, IMPL64)
DEF(ld_i64, 1, 1, 1, IMPL64)
DEF(st8_i64, 0, 2, 1, TCG_OPF_SIDE_EFFECTS | IMPL64)
DEF(st16_i64, 0, 2, 1, TCG_OPF_SIDE_EFFECTS | IMPL64)
DEF(st32_i64, 0, 2, 1, TCG_OPF_SIDE_EFFECTS | IMPL64)
DEF(st_i64, 0, 2, 1, TCG_OPF_SIDE_EFFECTS | IMPL64)
DEF(st8_i64, 0, 2, 1, IMPL64)
DEF(st16_i64, 0, 2, 1, IMPL64)
DEF(st32_i64, 0, 2, 1, IMPL64)
DEF(st_i64, 0, 2, 1, IMPL64)
/* arith */
DEF(add_i64, 1, 2, 0, IMPL64)
DEF(sub_i64, 1, 2, 0, IMPL64)