ARM: Fix RFE macrop.
This changes the RFE macroop into 3 microops:
URa = [sp]; URb = [sp+4]; // load CPSR,PC values from stack
sp = sp + offset; // optionally auto-increment
PC = URa; CPSR = URb; // write to the PC and CPSR.
Importantly:
- writing to PC is handled in the last micro-op.
- loading occurs prior to state changes.
diff --git a/src/arch/arm/isa/insts/ldr.isa b/src/arch/arm/isa/insts/ldr.isa
index c60a91a..2e45f28 100644
--- a/src/arch/arm/isa/insts/ldr.isa
+++ b/src/arch/arm/isa/insts/ldr.isa
@@ -67,7 +67,7 @@
self.memFlags = ["ArmISA::TLB::MustBeOne"]
self.codeBlobs = {"postacc_code" : ""}
- def emitHelper(self, base = 'Memory', wbDecl = None, instFlags = []):
+ def emitHelper(self, base = 'Memory', wbDecl = None, instFlags = [], pcDecl = None):
global header_output, decoder_output, exec_output
@@ -76,7 +76,8 @@
(newHeader,
newDecoder,
newExec) = self.fillTemplates(self.name, self.Name, codeBlobs,
- self.memFlags, instFlags, base, wbDecl)
+ self.memFlags, instFlags, base,
+ wbDecl, pcDecl)
header_output += newHeader
decoder_output += newDecoder
@@ -104,26 +105,18 @@
wbDiff = 8
accCode = '''
CPSR cpsr = Cpsr;
- SCTLR sctlr = Sctlr;
- // Use the version of NPC that gets set before NextThumb
- pNPC = cSwap<uint32_t>(Mem.ud, cpsr.e);
- uint32_t tempSpsr = cSwap<uint32_t>(Mem.ud >> 32, cpsr.e);
- uint32_t newCpsr =
- cpsrWriteByInstr(cpsr | CondCodes, tempSpsr,
- 0xF, true, sctlr.nmfi);
- Cpsr = ~CondCodesMask & newCpsr;
- NextThumb = ((CPSR)newCpsr).t;
- NextJazelle = ((CPSR)newCpsr).j;
- ForcedItState = ((((CPSR)tempSpsr).it2 << 2) & 0xFC)
- | (((CPSR)tempSpsr).it1 & 0x3);
- CondCodes = CondCodesMask & newCpsr;
+ URc = cpsr | CondCodes;
+ URa = cSwap<uint32_t>(Mem.ud, cpsr.e);
+ URb = cSwap<uint32_t>(Mem.ud >> 32, cpsr.e);
'''
self.codeBlobs["memacc_code"] = accCode
wbDecl = None
+ pcDecl = "MicroUopSetPCCPSR(machInst, INTREG_UREG0, INTREG_UREG1, INTREG_UREG2);"
+
if self.writeback:
wbDecl = "MicroAddiUop(machInst, base, base, %d);" % wbDiff
- self.emitHelper('RfeOp', wbDecl, ["IsSerializeAfter", "IsNonSpeculative"])
+ self.emitHelper('RfeOp', wbDecl, ["IsSerializeAfter", "IsNonSpeculative"], pcDecl)
class LoadImmInst(LoadInst):
def __init__(self, *args, **kargs):
diff --git a/src/arch/arm/isa/insts/macromem.isa b/src/arch/arm/isa/insts/macromem.isa
index 0e3bcc6..d6c9293 100644
--- a/src/arch/arm/isa/insts/macromem.isa
+++ b/src/arch/arm/isa/insts/macromem.isa
@@ -608,23 +608,48 @@
'predicate_test': predicateTest},
['IsMicroop'])
+ setPCCPSRDecl = '''
+ CPSR cpsrOrCondCodes = URc;
+ SCTLR sctlr = Sctlr;
+ pNPC = URa;
+ uint32_t newCpsr =
+ cpsrWriteByInstr(cpsrOrCondCodes, URb,
+ 0xF, true, sctlr.nmfi);
+ Cpsr = ~CondCodesMask & newCpsr;
+ NextThumb = ((CPSR)newCpsr).t;
+ NextJazelle = ((CPSR)newCpsr).j;
+ ForcedItState = ((((CPSR)URb).it2 << 2) & 0xFC)
+ | (((CPSR)URb).it1 & 0x3);
+ CondCodes = CondCodesMask & newCpsr;
+ '''
+
+ microUopSetPCCPSRIop = InstObjParams('uopSet_uop', 'MicroUopSetPCCPSR',
+ 'MicroSetPCCPSR',
+ {'code': setPCCPSRDecl,
+ 'predicate_test': predicateTest},
+ ['IsMicroop'])
+
header_output = MicroIntImmDeclare.subst(microAddiUopIop) + \
MicroIntImmDeclare.subst(microSubiUopIop) + \
MicroIntRegDeclare.subst(microAddUopIop) + \
MicroIntRegDeclare.subst(microSubUopIop) + \
- MicroIntMovDeclare.subst(microUopRegMovIop)
+ MicroIntMovDeclare.subst(microUopRegMovIop) + \
+ MicroSetPCCPSRDeclare.subst(microUopSetPCCPSRIop)
decoder_output = MicroIntImmConstructor.subst(microAddiUopIop) + \
MicroIntImmConstructor.subst(microSubiUopIop) + \
MicroIntRegConstructor.subst(microAddUopIop) + \
MicroIntRegConstructor.subst(microSubUopIop) + \
- MicroIntMovConstructor.subst(microUopRegMovIop)
+ MicroIntMovConstructor.subst(microUopRegMovIop) + \
+ MicroSetPCCPSRConstructor.subst(microUopSetPCCPSRIop)
exec_output = PredOpExecute.subst(microAddiUopIop) + \
PredOpExecute.subst(microSubiUopIop) + \
PredOpExecute.subst(microAddUopIop) + \
PredOpExecute.subst(microSubUopIop) + \
- PredOpExecute.subst(microUopRegMovIop)
+ PredOpExecute.subst(microUopRegMovIop) + \
+ PredOpExecute.subst(microUopSetPCCPSRIop)
+
}};
let {{
diff --git a/src/arch/arm/isa/insts/mem.isa b/src/arch/arm/isa/insts/mem.isa
index 507f8cd..d0c0f07 100644
--- a/src/arch/arm/isa/insts/mem.isa
+++ b/src/arch/arm/isa/insts/mem.isa
@@ -48,7 +48,7 @@
self.constructTemplate = eval(self.decConstBase + 'Constructor')
def fillTemplates(self, name, Name, codeBlobs, memFlags, instFlags,
- base = 'Memory', wbDecl = None):
+ base = 'Memory', wbDecl = None, pcDecl = None):
# Make sure flags are in lists (convert to lists if not).
memFlags = makeList(memFlags)
instFlags = makeList(instFlags)
@@ -65,12 +65,26 @@
macroName = Name
instFlagsCopy = list(instFlags)
codeBlobsCopy = dict(codeBlobs)
- if wbDecl is not None:
+
+ use_uops = 0
+ if wbDecl is not None or pcDecl is not None:
instFlagsCopy.append('IsMicroop')
Name = Name + 'Acc'
+ use_uops = 1
+
+ use_wb = 0
+ use_pc = 0
+ if wbDecl is not None:
+ use_wb = 1
+ if pcDecl is not None:
+ use_pc = 1
+
codeBlobsCopy['acc_name'] = Name
codeBlobsCopy['wb_decl'] = wbDecl
+ codeBlobsCopy['pc_decl'] = pcDecl
codeBlobsCopy['use_uops'] = 0
+ codeBlobsCopy['use_wb'] = 0
+ codeBlobsCopy['use_pc'] = 0
iop = InstObjParams(name, Name, base,
codeBlobsCopy, instFlagsCopy)
@@ -81,11 +95,14 @@
self.initiateAccTemplate.subst(iop) + \
self.completeAccTemplate.subst(iop)
- if wbDecl is not None:
+ if wbDecl is not None or pcDecl is not None:
iop = InstObjParams(name, macroName, base,
{ "wb_decl" : wbDecl,
+ "pc_decl" : pcDecl,
"acc_name" : Name,
- "use_uops" : 1 },
+ "use_uops" : use_uops,
+ "use_pc" : use_pc,
+ "use_wb" : use_wb },
['IsMacroop'])
header_output += self.declareTemplate.subst(iop)
decoder_output += self.constructTemplate.subst(iop)
