[WebAssembly] Support frame pointer

Add support for frame pointer use in prolog/epilog.
Supports dynamic allocas but not yet over-aligned locals.
Target-independend CG generates SP updates, but we still need to write
back the SP value to memory when necessary.

llvm-svn: 259220

1 files changed, 6 insertions, 1 deletions

diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyRegNumbering.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyRegNumbering.cpp
index a76cb81..f38f635 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyRegNumbering.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyRegNumbering.cpp
@@ -108,10 +108,15 @@ bool WebAssemblyRegNumbering::runOnMachineFunction(MachineFunction &MF) {
     }
   }
   // Allocate locals for used physical registers
-  if (FrameInfo.getStackSize() > 0) {
+  if (FrameInfo.getStackSize() > 0 || FrameInfo.adjustsStack()) {
     DEBUG(dbgs() << "PReg SP " << CurReg << "\n");
     MFI.addPReg(WebAssembly::SP32, CurReg++);
   }
+  bool HasFP = MF.getSubtarget().getFrameLowering()->hasFP(MF);
+  if (HasFP) {
+    DEBUG(dbgs() << "PReg FP " << CurReg << "\n");
+    MFI.addPReg(WebAssembly::FP32, CurReg++);
+  }
 
   return true;
 }