PNaCl: Add ExpandSmallArguments pass to widen parameters to 32 bits

This widens i1, i8 and i16 function arguments and return types.

Factor out RecreateFunction() helper function from existing PNaCl
passes since this is a reoccurring code fragment.

BUG=https://code.google.com/p/nativeclient/issues/detail?id=3342
TEST=*.ll tests + PNaCl toolchain trybots + GCC torture tests + LLVM test suite

Review URL: https://codereview.chromium.org/15971007

1 files changed, 10 insertions, 0 deletions

diff --git a/include/llvm/Transforms/NaCl.h b/include/llvm/Transforms/NaCl.h
index 92838e5fc7..cfd4c6e51d 100644
--- a/include/llvm/Transforms/NaCl.h
+++ b/include/llvm/Transforms/NaCl.h
@@ -13,7 +13,9 @@
 namespace llvm {
 
 class BasicBlockPass;
+class Function;
 class FunctionPass;
+class FunctionType;
 class Instruction;
 class ModulePass;
 class PassManager;
@@ -26,6 +28,7 @@ ModulePass *createExpandByValPass();
 FunctionPass *createExpandConstantExprPass();
 ModulePass *createExpandCtorsPass();
 BasicBlockPass *createExpandGetElementPtrPass();
+ModulePass *createExpandSmallArgumentsPass();
 ModulePass *createExpandTlsPass();
 ModulePass *createExpandTlsConstantExprPass();
 ModulePass *createExpandVarArgsPass();
@@ -48,6 +51,13 @@ void PhiSafeReplaceUses(Use *U, Value *NewVal);
 // Copy debug information from Original to NewInst, and return NewInst.
 Instruction *CopyDebug(Instruction *NewInst, Instruction *Original);
 
+// In order to change a function's type, the function must be
+// recreated.  RecreateFunction() recreates Func with type NewType.
+// It copies or moves across everything except the argument values,
+// which the caller must update because the argument types might be
+// different.
+Function *RecreateFunction(Function *Func, FunctionType *NewType);
+
 }
 
 #endif