From e656730f356edf86879abc522862c267c90ab3de Mon Sep 17 00:00:00 2001 From: Gabe Black Date: Thu, 28 Jan 2021 17:18:26 -0800 Subject: [PATCH] arch-arm,cpu: Introduce a getEMI virtual method on StaticInst. This takes the place of direct access to the machInst field as used in the MinorCPU model which makes the incorrect assumption that it can arbitrarily treat the ExtMachInst as an integer, and that masking in a certain way can meaningfully classify what the instruction will do. Because that assumption is not correct in general, that had been ifdef-ed out in most ISAs except ARM, and for the other ISAs the value was simply set to zero. Change-Id: I8ac05e65475edc3ccc044afdff09490e2c05ba07 Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/40098 Reviewed-by: Giacomo Travaglini Maintainer: Giacomo Travaglini Maintainer: Bobby R. Bruce Tested-by: kokoro --- src/arch/arm/insts/static_inst.hh | 2 ++ src/cpu/minor/func_unit.cc | 13 ++++++------- src/cpu/static_inst.hh | 2 ++ 3 files changed, 10 insertions(+), 7 deletions(-) diff --git a/src/arch/arm/insts/static_inst.hh b/src/arch/arm/insts/static_inst.hh index e101d93fa8..908641c49f 100644 --- a/src/arch/arm/insts/static_inst.hh +++ b/src/arch/arm/insts/static_inst.hh @@ -197,6 +197,8 @@ class ArmStaticInst : public StaticInst pcState.advance(); } + uint64_t getEMI() const override { return machInst; } + std::string generateDisassembly( Addr pc, const Loader::SymbolTable *symtab) const override; diff --git a/src/cpu/minor/func_unit.cc b/src/cpu/minor/func_unit.cc index 58f3a1e721..8c5e3a6bb4 100644 --- a/src/cpu/minor/func_unit.cc +++ b/src/cpu/minor/func_unit.cc @@ -171,13 +171,12 @@ FUPipeline::advance() MinorFUTiming * FUPipeline::findTiming(const StaticInstPtr &inst) { -#if THE_ISA == ARM_ISA - /* This should work for any ISA with a POD mach_inst */ - TheISA::ExtMachInst mach_inst = inst->machInst; -#else - /* Just allow extra decode based on op classes */ - uint64_t mach_inst = 0; -#endif + /* + * This will only work on ISAs with an instruction format with a fixed size + * which can be categorized using bit masks. This is really only supported + * on ARM and is a bit of a hack. + */ + uint64_t mach_inst = inst->getEMI(); const std::vector &timings = description.timings; diff --git a/src/cpu/static_inst.hh b/src/cpu/static_inst.hh index 09f171f5ba..b2cd50851b 100644 --- a/src/cpu/static_inst.hh +++ b/src/cpu/static_inst.hh @@ -258,6 +258,8 @@ class StaticInst : public RefCounted, public StaticInstFlags /// The binary machine instruction. const TheISA::ExtMachInst machInst; + virtual uint64_t getEMI() const { return 0; } + protected: /**