#include "llvm/ADT/StringExtras.h"
#include "llvm/Attributes.h"
#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/MathExtras.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetData.h"
}
}
+static llvm::Value *EmitVAArgFromMemory(llvm::Value *VAListAddr,
+ QualType Ty,
+ CodeGenFunction &CGF) {
+ llvm::Value *overflow_arg_area_p =
+ CGF.Builder.CreateStructGEP(VAListAddr, 2, "overflow_arg_area_p");
+ llvm::Value *overflow_arg_area =
+ CGF.Builder.CreateLoad(overflow_arg_area_p, "overflow_arg_area");
+
+ // AMD64-ABI 3.5.7p5: Step 7. Align l->overflow_arg_area upwards to a 16
+ // byte boundary if alignment needed by type exceeds 8 byte boundary.
+ uint64_t Align = llvm::NextPowerOf2(CGF.getContext().getTypeAlign(Ty) / 8);
+ if (Align > 8) {
+ // Note align to type alignment instead of assuming it must be 16.
+
+ // FIXME: Implement alignment in x86_64 va_arg.
+ }
+
+ // AMD64-ABI 3.5.7p5: Step 8. Fetch type from l->overflow_arg_area.
+ const llvm::Type *LTy = CGF.ConvertTypeForMem(Ty);
+ llvm::Value *Res =
+ CGF.Builder.CreateBitCast(overflow_arg_area,
+ llvm::PointerType::getUnqual(LTy));
+
+ // AMD64-ABI 3.5.7p5: Step 9. Set l->overflow_arg_area to:
+ // l->overflow_arg_area + sizeof(type).
+ // AMD64-ABI 3.5.7p5: Step 10. Align l->overflow_arg_area upwards to
+ // an 8 byte boundary.
+
+ uint64_t SizeInBytes = (CGF.getContext().getTypeSize(Ty) + 7) / 8;
+ llvm::Value *Offset = llvm::ConstantInt::get(llvm::Type::Int32Ty,
+ (SizeInBytes + 7) & ~7);
+ overflow_arg_area = CGF.Builder.CreateGEP(overflow_arg_area, Offset,
+ "overflow_arg_area.next");
+ CGF.Builder.CreateStore(overflow_arg_area, overflow_arg_area_p);
+
+ // AMD64-ABI 3.5.7p5: Step 11. Return the fetched type.
+ return Res;
+}
+
llvm::Value *X86_64ABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
CodeGenFunction &CGF) const {
- return 0;
+ // Assume that va_list type is correct; should be pointer to LLVM type:
+ // struct {
+ // i32 gp_offset;
+ // i32 fp_offset;
+ // i8* overflow_arg_area;
+ // i8* reg_save_area;
+ // };
+ unsigned neededInt, neededSSE;
+ ABIArgInfo AI = classifyArgumentType(Ty, CGF.getContext(),
+ neededInt, neededSSE);
+
+ // AMD64-ABI 3.5.7p5: Step 1. Determine whether type may be passed
+ // in the registers. If not go to step 7.
+ if (!neededInt && !neededSSE)
+ return EmitVAArgFromMemory(VAListAddr, Ty, CGF);
+
+ // AMD64-ABI 3.5.7p5: Step 2. Compute num_gp to hold the number of
+ // general purpose registers needed to pass type and num_fp to hold
+ // the number of floating point registers needed.
+
+ // AMD64-ABI 3.5.7p5: Step 3. Verify whether arguments fit into
+ // registers. In the case: l->gp_offset > 48 - num_gp * 8 or
+ // l->fp_offset > 304 - num_fp * 16 go to step 7.
+ //
+ // NOTE: 304 is a typo, there are (6 * 8 + 8 * 16) = 176 bytes of
+ // register save space).
+
+ llvm::Value *InRegs = 0;
+ llvm::Value *gp_offset_p = 0, *gp_offset = 0;
+ llvm::Value *fp_offset_p = 0, *fp_offset = 0;
+ if (neededInt) {
+ gp_offset_p = CGF.Builder.CreateStructGEP(VAListAddr, 0, "gp_offset_p");
+ gp_offset = CGF.Builder.CreateLoad(gp_offset_p, "gp_offset");
+ InRegs =
+ CGF.Builder.CreateICmpULE(gp_offset,
+ llvm::ConstantInt::get(llvm::Type::Int32Ty,
+ 48 - neededInt * 8),
+ "fits_in_gp");
+ }
+
+ if (neededSSE) {
+ fp_offset_p = CGF.Builder.CreateStructGEP(VAListAddr, 1, "fp_offset_p");
+ fp_offset = CGF.Builder.CreateLoad(fp_offset_p, "fp_offset");
+ llvm::Value *FitsInFP =
+ CGF.Builder.CreateICmpULE(fp_offset,
+ llvm::ConstantInt::get(llvm::Type::Int32Ty,
+ 176 - neededSSE * 8),
+ "fits_in_fp");
+ InRegs = InRegs ? CGF.Builder.CreateOr(InRegs, FitsInFP) : FitsInFP;
+ }
+
+ llvm::BasicBlock *InRegBlock = CGF.createBasicBlock("vaarg.in_reg");
+ llvm::BasicBlock *InMemBlock = CGF.createBasicBlock("vaarg.in_mem");
+ llvm::BasicBlock *ContBlock = CGF.createBasicBlock("vaarg.end");
+ CGF.Builder.CreateCondBr(InRegs, InRegBlock, InMemBlock);
+
+ // Emit code to load the value if it was passed in registers.
+
+ CGF.EmitBlock(InRegBlock);
+
+ // AMD64-ABI 3.5.7p5: Step 4. Fetch type from l->reg_save_area with
+ // an offset of l->gp_offset and/or l->fp_offset. This may require
+ // copying to a temporary location in case the parameter is passed
+ // in different register classes or requires an alignment greater
+ // than 8 for general purpose registers and 16 for XMM registers.
+ const llvm::Type *LTy = CGF.ConvertTypeForMem(Ty);
+ llvm::Value *RegAddr =
+ CGF.Builder.CreateLoad(CGF.Builder.CreateStructGEP(VAListAddr, 3),
+ "reg_save_area");
+ if (neededInt && neededSSE) {
+ assert(0 && "FIXME: Implement support for va_arg in mixed regs");
+ } else if (neededInt) {
+ RegAddr = CGF.Builder.CreateGEP(RegAddr, gp_offset);
+ RegAddr = CGF.Builder.CreateBitCast(RegAddr,
+ llvm::PointerType::getUnqual(LTy));
+ } else {
+ RegAddr = CGF.Builder.CreateGEP(RegAddr, fp_offset);
+ RegAddr = CGF.Builder.CreateBitCast(RegAddr,
+ llvm::PointerType::getUnqual(LTy));
+ }
+
+ // AMD64-ABI 3.5.7p5: Step 5. Set:
+ // l->gp_offset = l->gp_offset + num_gp * 8
+ // l->fp_offset = l->fp_offset + num_fp * 16.
+ if (neededInt) {
+ llvm::Value *Offset = llvm::ConstantInt::get(llvm::Type::Int32Ty,
+ neededInt * 8);
+ CGF.Builder.CreateStore(CGF.Builder.CreateAdd(gp_offset, Offset),
+ gp_offset_p);
+ }
+ if (neededSSE) {
+ llvm::Value *Offset = llvm::ConstantInt::get(llvm::Type::Int32Ty,
+ neededSSE * 16);
+ CGF.Builder.CreateStore(CGF.Builder.CreateAdd(fp_offset, Offset),
+ fp_offset_p);
+ }
+ CGF.EmitBranch(ContBlock);
+
+ // Emit code to load the value if it was passed in memory.
+
+ CGF.EmitBlock(InMemBlock);
+ llvm::Value *MemAddr = EmitVAArgFromMemory(VAListAddr, Ty, CGF);
+
+ // Return the appropriate result.
+
+ CGF.EmitBlock(ContBlock);
+ llvm::PHINode *ResAddr = CGF.Builder.CreatePHI(RegAddr->getType(),
+ "vaarg.addr");
+ ResAddr->reserveOperandSpace(2);
+ ResAddr->addIncoming(RegAddr, InRegBlock);
+ ResAddr->addIncoming(MemAddr, InMemBlock);
+
+ return ResAddr;
}
ABIArgInfo DefaultABIInfo::classifyReturnType(QualType RetTy,
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