From b202d41ee705a7a6152d03eb362e2e2147505022 Mon Sep 17 00:00:00 2001 From: Aurelien Jarno Date: Tue, 9 Oct 2012 21:53:08 +0200 Subject: tcg: forbid ld/st function to modify globals 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 Signed-off-by: Aurelien Jarno --- tcg/README | 3 +++ tcg/tcg-opc.h | 14 +++++++------- 2 files changed, 10 insertions(+), 7 deletions(-) (limited to 'tcg') diff --git a/tcg/README b/tcg/README index aa86992bca..9d1b100613 100644 --- a/tcg/README +++ b/tcg/README @@ -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 diff --git a/tcg/tcg-opc.h b/tcg/tcg-opc.h index 2072281103..9651063414 100644 --- a/tcg/tcg-opc.h +++ b/tcg/tcg-opc.h @@ -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) -- cgit v1.2.3