[Sparc] Generate correct code for leaf functions with stack objects

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@183067 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/Sparc/SparcSubtarget.cpp

@@ -13,6 +13,7 @@
 
 #include "SparcSubtarget.h"
 #include "Sparc.h"
+#include "llvm/Support/MathExtras.h"
 #include "llvm/Support/TargetRegistry.h"
 
 #define GET_SUBTARGETINFO_TARGET_DESC
@@ -44,3 +45,30 @@ SparcSubtarget::SparcSubtarget(const std::string &TT, const std::string &CPU,
   // Parse features string.
   ParseSubtargetFeatures(CPUName, FS);
 }
+
+
+int SparcSubtarget::getAdjustedFrameSize(int frameSize) const {
+
+  if (is64Bit()) {
+    // All 64-bit stack frames must be 16-byte aligned, and must reserve space
+    // for spilling the 16 window registers at %sp+BIAS..%sp+BIAS+128.
+    frameSize += 128;
+    // Frames with calls must also reserve space for 6 outgoing arguments
+    // whether they are used or not. LowerCall_64 takes care of that.
+    assert(frameSize % 16 == 0 && "Stack size not 16-byte aligned");
+  } else {
+    // Emit the correct save instruction based on the number of bytes in
+    // the frame. Minimum stack frame size according to V8 ABI is:
+    //   16 words for register window spill
+    //    1 word for address of returned aggregate-value
+    // +  6 words for passing parameters on the stack
+    // ----------
+    //   23 words * 4 bytes per word = 92 bytes
+    frameSize += 92;
+
+    // Round up to next doubleword boundary -- a double-word boundary
+    // is required by the ABI.
+    frameSize = RoundUpToAlignment(frameSize, 8);
+  }
+  return frameSize;
+}