Make library calls sensitive to regparm module flag (Fixes PR3997).

Reviewers: mkuper, rnk

Subscribers: mehdi_amini, jyknight, aemerson, llvm-commits, rengolin

Differential Revision: https://reviews.llvm.org/D27050

llvm-svn: 298179

1 files changed, 41 insertions, 7 deletions

diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index 68b5ab5ce20..5ba64d37193 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -53,6 +53,7 @@
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/MathExtras.h"
+#include "llvm/Target/TargetLowering.h"
 #include "llvm/Target/TargetOptions.h"
 #include <algorithm>
 #include <bitset>
@@ -1961,6 +1962,34 @@ bool X86TargetLowering::useSoftFloat() const {
   return Subtarget.useSoftFloat();
 }
 
+void X86TargetLowering::markLibCallAttributes(MachineFunction *MF, unsigned CC,
+                                              ArgListTy &Args) const {
+
+  // Only relabel X86-32 for C / Stdcall CCs.
+  if (static_cast<const X86Subtarget &>(MF->getSubtarget()).is64Bit())
+    return;
+  if (CC != CallingConv::C && CC != CallingConv::X86_StdCall)
+    return;
+  unsigned ParamRegs = 0;
+  if (auto *M = MF->getFunction()->getParent())
+    ParamRegs = M->getNumberRegisterParameters();
+
+  // Mark the first N int arguments as having reg
+  for (unsigned Idx = 0; Idx < Args.size(); Idx++) {
+    Type *T = Args[Idx].Ty;
+    if (T->isPointerTy() || T->isIntegerTy())
+      if (MF->getDataLayout().getTypeAllocSize(T) <= 8) {
+        unsigned numRegs = 1;
+        if (MF->getDataLayout().getTypeAllocSize(T) > 4)
+          numRegs = 2;
+        if (ParamRegs < numRegs)
+          return;
+        ParamRegs -= numRegs;
+        Args[Idx].IsInReg = true;
+      }
+  }
+}
+
 const MCExpr *
 X86TargetLowering::LowerCustomJumpTableEntry(const MachineJumpTableInfo *MJTI,
                                              const MachineBasicBlock *MBB,
@@ -21517,11 +21546,15 @@ SDValue X86TargetLowering::LowerWin64_i128OP(SDValue Op, SelectionDAG &DAG) cons
                                          getPointerTy(DAG.getDataLayout()));
 
   TargetLowering::CallLoweringInfo CLI(DAG);
-  CLI.setDebugLoc(dl).setChain(InChain)
-    .setCallee(getLibcallCallingConv(LC),
-               static_cast<EVT>(MVT::v2i64).getTypeForEVT(*DAG.getContext()),
-               Callee, std::move(Args))
-    .setInRegister().setSExtResult(isSigned).setZExtResult(!isSigned);
+  CLI.setDebugLoc(dl)
+      .setChain(InChain)
+      .setLibCallee(
+          getLibcallCallingConv(LC),
+          static_cast<EVT>(MVT::v2i64).getTypeForEVT(*DAG.getContext()), Callee,
+          std::move(Args))
+      .setInRegister()
+      .setSExtResult(isSigned)
+      .setZExtResult(!isSigned);
 
   std::pair<SDValue, SDValue> CallInfo = LowerCallTo(CLI);
   return DAG.getBitcast(VT, CallInfo.first);
@@ -23245,8 +23278,9 @@ static SDValue LowerFSINCOS(SDValue Op, const X86Subtarget &Subtarget,
     : (Type*)VectorType::get(ArgTy, 4);
 
   TargetLowering::CallLoweringInfo CLI(DAG);
-  CLI.setDebugLoc(dl).setChain(DAG.getEntryNode())
-    .setCallee(CallingConv::C, RetTy, Callee, std::move(Args));
+  CLI.setDebugLoc(dl)
+      .setChain(DAG.getEntryNode())
+      .setLibCallee(CallingConv::C, RetTy, Callee, std::move(Args));
 
   std::pair<SDValue, SDValue> CallResult = TLI.LowerCallTo(CLI);