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We currently have 3 different ways of computing the architectural value of "PC" as seen in the ARM ARM. The value of s->pc has been incremented past the current insn, but that is all. Thus for a32, PC = s->pc + 4; for t32, PC = s->pc; for t16, PC = s->pc + 2. These differing computations make it impossible at present to unify the various code paths. With the newly introduced s->pc_curr, we can compute the correct value for all cases, using the formula given in the ARM ARM. This changes the behaviour for load_reg() and load_reg_var() when called with reg==15 from a 32-bit Thumb instruction: previously they would have returned the incorrect value of pc_curr + 6, and now they will return the architecturally correct value of PC, which is pc_curr + 4. This will not affect well-behaved guest software, because all of the places we call these functions from T32 code are instructions where using r15 is UNPREDICTABLE. Using the architectural PC value here is more consistent with the T16 and A32 behaviour. Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-id: 20190807045335.1361-4-richard.henderson@linaro.org [PMM: added commit message note about UNPREDICTABLE T32 cases] Signed-off-by: Peter Maydell <peter.maydell@linaro.org> |
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| .. | ||
| arch_dump.c | ||
| arm_ldst.h | ||
| arm-powerctl.c | ||
| arm-powerctl.h | ||
| arm-semi.c | ||
| cpu64.c | ||
| cpu-param.h | ||
| cpu-qom.h | ||
| cpu.c | ||
| cpu.h | ||
| crypto_helper.c | ||
| debug_helper.c | ||
| gdbstub64.c | ||
| gdbstub.c | ||
| helper-a64.c | ||
| helper-a64.h | ||
| helper-sve.h | ||
| helper.c | ||
| helper.h | ||
| idau.h | ||
| internals.h | ||
| iwmmxt_helper.c | ||
| kvm32.c | ||
| kvm64.c | ||
| kvm_arm.h | ||
| kvm-consts.h | ||
| kvm-stub.c | ||
| kvm.c | ||
| m_helper.c | ||
| machine.c | ||
| Makefile.objs | ||
| monitor.c | ||
| neon_helper.c | ||
| op_addsub.h | ||
| op_helper.c | ||
| pauth_helper.c | ||
| psci.c | ||
| sve_helper.c | ||
| sve.decode | ||
| tlb_helper.c | ||
| trace-events | ||
| translate-a64.c | ||
| translate-a64.h | ||
| translate-sve.c | ||
| translate-vfp.inc.c | ||
| translate.c | ||
| translate.h | ||
| vec_helper.c | ||
| vfp_helper.c | ||
| vfp-uncond.decode | ||
| vfp.decode | ||