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-rw-r--r--include/llvm/Analysis/AliasAnalysis.h18
-rw-r--r--lib/Analysis/AliasAnalysis.cpp2
-rw-r--r--lib/Analysis/BasicAliasAnalysis.cpp14
-rw-r--r--lib/Analysis/IPA/GlobalsModRef.cpp29
-rw-r--r--lib/Analysis/TypeBasedAliasAnalysis.cpp3
-rw-r--r--lib/Transforms/IPO/FunctionAttrs.cpp75
-rw-r--r--test/Transforms/FunctionAttrs/2008-09-03-ReadNone.ll2
-rw-r--r--test/Transforms/FunctionAttrs/2008-09-03-ReadOnly.ll2
8 files changed, 71 insertions, 74 deletions
diff --git a/include/llvm/Analysis/AliasAnalysis.h b/include/llvm/Analysis/AliasAnalysis.h
index 841513b715..6b716ddee9 100644
--- a/include/llvm/Analysis/AliasAnalysis.h
+++ b/include/llvm/Analysis/AliasAnalysis.h
@@ -175,6 +175,9 @@ public:
///
enum ModRefResult { NoModRef = 0, Ref = 1, Mod = 2, ModRef = 3 };
+ /// These values define additional bits used to define the
+ /// ModRefBehavior values.
+ enum { Nowhere = 0, ArgumentPointees = 4, Anywhere = 8 | ArgumentPointees };
/// ModRefBehavior - Summary of how a function affects memory in the program.
/// Loads from constant globals are not considered memory accesses for this
@@ -187,20 +190,20 @@ public:
/// This property corresponds to the GCC 'const' attribute.
/// This property corresponds to the LLVM IR 'readnone' attribute.
/// This property corresponds to the IntrNoMem LLVM intrinsic flag.
- DoesNotAccessMemory,
+ DoesNotAccessMemory = Nowhere | NoModRef,
/// AccessesArgumentsReadonly - This function loads through function
/// arguments and does not perform any non-local stores or volatile
/// loads.
///
/// This property corresponds to the IntrReadArgMem LLVM intrinsic flag.
- AccessesArgumentsReadonly,
+ AccessesArgumentsReadonly = ArgumentPointees | Ref,
/// AccessesArguments - This function accesses function arguments in well
/// known (possibly volatile) ways, but does not access any other memory.
///
/// This property corresponds to the IntrReadWriteArgMem LLVM intrinsic flag.
- AccessesArguments,
+ AccessesArguments = ArgumentPointees | ModRef,
/// OnlyReadsMemory - This function does not perform any non-local stores or
/// volatile loads, but may read from any memory location.
@@ -208,11 +211,11 @@ public:
/// This property corresponds to the GCC 'pure' attribute.
/// This property corresponds to the LLVM IR 'readonly' attribute.
/// This property corresponds to the IntrReadMem LLVM intrinsic flag.
- OnlyReadsMemory,
+ OnlyReadsMemory = Anywhere | Ref,
/// UnknownModRefBehavior - This indicates that the function could not be
/// classified into one of the behaviors above.
- UnknownModRefBehavior
+ UnknownModRefBehavior = Anywhere | ModRef
};
/// getModRefBehavior - Return the behavior when calling the given call site.
@@ -270,12 +273,9 @@ public:
/// true. For use when the call site is not known.
///
static bool onlyReadsMemory(ModRefBehavior MRB) {
- return MRB == DoesNotAccessMemory ||
- MRB == AccessesArgumentsReadonly ||
- MRB == OnlyReadsMemory;
+ return !(MRB & Mod);
}
-
/// getModRefInfo - Return information about whether or not an instruction may
/// read or write the specified memory location. An instruction
/// that doesn't read or write memory may be trivially LICM'd for example.
diff --git a/lib/Analysis/AliasAnalysis.cpp b/lib/Analysis/AliasAnalysis.cpp
index 7f9c9c169e..363da9fcee 100644
--- a/lib/Analysis/AliasAnalysis.cpp
+++ b/lib/Analysis/AliasAnalysis.cpp
@@ -179,7 +179,7 @@ AliasAnalysis::getModRefBehavior(ImmutableCallSite CS) {
// Otherwise, fall back to the next AA in the chain. But we can merge
// in any result we've managed to compute.
- return std::min(AA->getModRefBehavior(CS), Min);
+ return ModRefBehavior(AA->getModRefBehavior(CS) & Min);
}
AliasAnalysis::ModRefBehavior
diff --git a/lib/Analysis/BasicAliasAnalysis.cpp b/lib/Analysis/BasicAliasAnalysis.cpp
index 73114fe5aa..bf1b689587 100644
--- a/lib/Analysis/BasicAliasAnalysis.cpp
+++ b/lib/Analysis/BasicAliasAnalysis.cpp
@@ -595,7 +595,7 @@ BasicAliasAnalysis::getModRefBehavior(ImmutableCallSite CS) {
Min = OnlyReadsMemory;
// The AliasAnalysis base class has some smarts, lets use them.
- return std::min(AliasAnalysis::getModRefBehavior(CS), Min);
+ return ModRefBehavior(AliasAnalysis::getModRefBehavior(CS) & Min);
}
/// getModRefBehavior - Return the behavior when calling the given function.
@@ -613,12 +613,14 @@ BasicAliasAnalysis::getModRefBehavior(const Function *F) {
#undef GET_INTRINSIC_MODREF_BEHAVIOR
}
+ ModRefBehavior Min = UnknownModRefBehavior;
+
// If the function declares it only reads memory, go with that.
if (F->onlyReadsMemory())
- return OnlyReadsMemory;
+ Min = OnlyReadsMemory;
// Otherwise be conservative.
- return AliasAnalysis::getModRefBehavior(F);
+ return ModRefBehavior(AliasAnalysis::getModRefBehavior(F) & Min);
}
/// getModRefInfo - Check to see if the specified callsite can clobber the
@@ -671,6 +673,8 @@ BasicAliasAnalysis::getModRefInfo(ImmutableCallSite CS,
return NoModRef;
}
+ ModRefResult Min = ModRef;
+
// Finally, handle specific knowledge of intrinsics.
const IntrinsicInst *II = dyn_cast<IntrinsicInst>(CS.getInstruction());
if (II != 0)
@@ -686,7 +690,7 @@ BasicAliasAnalysis::getModRefInfo(ImmutableCallSite CS,
if (isNoAlias(Location(Dest, Len), Loc)) {
if (isNoAlias(Location(Src, Len), Loc))
return NoModRef;
- return Ref;
+ Min = Ref;
}
break;
}
@@ -745,7 +749,7 @@ BasicAliasAnalysis::getModRefInfo(ImmutableCallSite CS,
}
// The AliasAnalysis base class has some smarts, lets use them.
- return AliasAnalysis::getModRefInfo(CS, Loc);
+ return ModRefResult(AliasAnalysis::getModRefInfo(CS, Loc) & Min);
}
/// aliasGEP - Provide a bunch of ad-hoc rules to disambiguate a GEP instruction
diff --git a/lib/Analysis/IPA/GlobalsModRef.cpp b/lib/Analysis/IPA/GlobalsModRef.cpp
index 6e4fff7b52..456a80a972 100644
--- a/lib/Analysis/IPA/GlobalsModRef.cpp
+++ b/lib/Analysis/IPA/GlobalsModRef.cpp
@@ -120,28 +120,33 @@ namespace {
/// called from the specified call site. The call site may be null in which
/// case the most generic behavior of this function should be returned.
ModRefBehavior getModRefBehavior(const Function *F) {
+ ModRefBehavior Min = UnknownModRefBehavior;
+
if (FunctionRecord *FR = getFunctionInfo(F)) {
if (FR->FunctionEffect == 0)
- return DoesNotAccessMemory;
+ Min = DoesNotAccessMemory;
else if ((FR->FunctionEffect & Mod) == 0)
- return OnlyReadsMemory;
+ Min = OnlyReadsMemory;
}
- return AliasAnalysis::getModRefBehavior(F);
+
+ return ModRefBehavior(AliasAnalysis::getModRefBehavior(F) & Min);
}
/// getModRefBehavior - Return the behavior of the specified function if
/// called from the specified call site. The call site may be null in which
/// case the most generic behavior of this function should be returned.
ModRefBehavior getModRefBehavior(ImmutableCallSite CS) {
- const Function* F = CS.getCalledFunction();
- if (!F) return AliasAnalysis::getModRefBehavior(CS);
- if (FunctionRecord *FR = getFunctionInfo(F)) {
- if (FR->FunctionEffect == 0)
- return DoesNotAccessMemory;
- else if ((FR->FunctionEffect & Mod) == 0)
- return OnlyReadsMemory;
- }
- return AliasAnalysis::getModRefBehavior(CS);
+ ModRefBehavior Min = UnknownModRefBehavior;
+
+ if (const Function* F = CS.getCalledFunction())
+ if (FunctionRecord *FR = getFunctionInfo(F)) {
+ if (FR->FunctionEffect == 0)
+ Min = DoesNotAccessMemory;
+ else if ((FR->FunctionEffect & Mod) == 0)
+ Min = OnlyReadsMemory;
+ }
+
+ return ModRefBehavior(AliasAnalysis::getModRefBehavior(CS) & Min);
}
virtual void deleteValue(Value *V);
diff --git a/lib/Analysis/TypeBasedAliasAnalysis.cpp b/lib/Analysis/TypeBasedAliasAnalysis.cpp
index 16ff64e4cf..46c9aa95a9 100644
--- a/lib/Analysis/TypeBasedAliasAnalysis.cpp
+++ b/lib/Analysis/TypeBasedAliasAnalysis.cpp
@@ -256,11 +256,12 @@ TypeBasedAliasAnalysis::getModRefBehavior(ImmutableCallSite CS) {
if (TBAANode(M).TypeIsImmutable())
Min = OnlyReadsMemory;
- return std::min(AliasAnalysis::getModRefBehavior(CS), Min);
+ return ModRefBehavior(AliasAnalysis::getModRefBehavior(CS) & Min);
}
AliasAnalysis::ModRefBehavior
TypeBasedAliasAnalysis::getModRefBehavior(const Function *F) {
+ // Functions don't have metadata. Just chain to the next implementation.
return AliasAnalysis::getModRefBehavior(F);
}
diff --git a/lib/Transforms/IPO/FunctionAttrs.cpp b/lib/Transforms/IPO/FunctionAttrs.cpp
index 8bdf5d75da..3b1b13d378 100644
--- a/lib/Transforms/IPO/FunctionAttrs.cpp
+++ b/lib/Transforms/IPO/FunctionAttrs.cpp
@@ -128,54 +128,41 @@ bool FunctionAttrs::AddReadAttrs(const CallGraphSCC &SCC) {
// Ignore calls to functions in the same SCC.
if (CS.getCalledFunction() && SCCNodes.count(CS.getCalledFunction()))
continue;
- switch (AA->getModRefBehavior(CS)) {
- case AliasAnalysis::DoesNotAccessMemory:
- // Ignore calls that don't access memory.
- continue;
- case AliasAnalysis::OnlyReadsMemory:
- // Handle calls that only read from memory.
- ReadsMemory = true;
- continue;
- case AliasAnalysis::AccessesArguments:
- // Check whether all pointer arguments point to local memory, and
- // ignore calls that only access local memory.
- for (CallSite::arg_iterator CI = CS.arg_begin(), CE = CS.arg_end();
- CI != CE; ++CI) {
- Value *Arg = *CI;
- if (Arg->getType()->isPointerTy()) {
- AliasAnalysis::Location Loc(Arg,
- AliasAnalysis::UnknownSize,
- I->getMetadata(LLVMContext::MD_tbaa));
- if (!AA->pointsToConstantMemory(Loc, /*OrLocal=*/true))
- // Writes memory. Just give up.
- return false;
- }
- }
- // Only reads and writes local memory.
- continue;
- case AliasAnalysis::AccessesArgumentsReadonly:
- // Check whether all pointer arguments point to local memory, and
- // ignore calls that only access local memory.
- for (CallSite::arg_iterator CI = CS.arg_begin(), CE = CS.arg_end();
- CI != CE; ++CI) {
- Value *Arg = *CI;
- if (Arg->getType()->isPointerTy()) {
- AliasAnalysis::Location Loc(Arg,
- AliasAnalysis::UnknownSize,
- I->getMetadata(LLVMContext::MD_tbaa));
- if (!AA->pointsToConstantMemory(Loc, /*OrLocal=*/true)) {
- // Reads non-local memory.
- ReadsMemory = true;
- break;
+ AliasAnalysis::ModRefBehavior MRB = AA->getModRefBehavior(CS);
+ // If the call doesn't access arbitrary memory, we may be able to
+ // figure out something.
+ if (!(MRB & AliasAnalysis::Anywhere &
+ ~AliasAnalysis::ArgumentPointees)) {
+ // If the call accesses argument pointees, check each argument.
+ if (MRB & AliasAnalysis::AccessesArguments)
+ // Check whether all pointer arguments point to local memory, and
+ // ignore calls that only access local memory.
+ for (CallSite::arg_iterator CI = CS.arg_begin(), CE = CS.arg_end();
+ CI != CE; ++CI) {
+ Value *Arg = *CI;
+ if (Arg->getType()->isPointerTy()) {
+ AliasAnalysis::Location Loc(Arg,
+ AliasAnalysis::UnknownSize,
+ I->getMetadata(LLVMContext::MD_tbaa));
+ if (!AA->pointsToConstantMemory(Loc, /*OrLocal=*/true)) {
+ if (MRB & AliasAnalysis::Mod)
+ // Writes non-local memory. Give up.
+ return false;
+ if (MRB & AliasAnalysis::Ref)
+ // Ok, it reads non-local memory.
+ ReadsMemory = true;
+ }
}
}
- }
- // Only reads memory.
continue;
- default:
- // Otherwise, be conservative.
- break;
}
+ // The call could access any memory. If that includes writes, give up.
+ if (MRB & AliasAnalysis::Mod)
+ return false;
+ // If it reads, note it.
+ if (MRB & AliasAnalysis::Ref)
+ ReadsMemory = true;
+ continue;
} else if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
// Ignore non-volatile loads from local memory.
if (!LI->isVolatile()) {
diff --git a/test/Transforms/FunctionAttrs/2008-09-03-ReadNone.ll b/test/Transforms/FunctionAttrs/2008-09-03-ReadNone.ll
index 535a1d0fba..946453f586 100644
--- a/test/Transforms/FunctionAttrs/2008-09-03-ReadNone.ll
+++ b/test/Transforms/FunctionAttrs/2008-09-03-ReadNone.ll
@@ -1,4 +1,4 @@
-; RUN: opt < %s -functionattrs -S | grep readnone | count 4
+; RUN: opt < %s -basicaa -functionattrs -S | grep readnone | count 4
@x = global i32 0
declare i32 @e() readnone
diff --git a/test/Transforms/FunctionAttrs/2008-09-03-ReadOnly.ll b/test/Transforms/FunctionAttrs/2008-09-03-ReadOnly.ll
index b455fdd8c3..22eca13204 100644
--- a/test/Transforms/FunctionAttrs/2008-09-03-ReadOnly.ll
+++ b/test/Transforms/FunctionAttrs/2008-09-03-ReadOnly.ll
@@ -1,4 +1,4 @@
-; RUN: opt < %s -functionattrs -S | grep readonly | count 2
+; RUN: opt < %s -basicaa -functionattrs -S | grep readonly | count 2
define i32 @f() {
entry:
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-16 08:24:50 +0000