implement support for the linux/ppc function call ABI. Patch by

Nicolas Geoffray!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34574 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 35 insertions, 15 deletions

diff --git a/lib/Target/PowerPC/PPCFrameInfo.h b/lib/Target/PowerPC/PPCFrameInfo.h
index 22b945ea20..0c72824730 100644
--- a/lib/Target/PowerPC/PPCFrameInfo.h
+++ b/lib/Target/PowerPC/PPCFrameInfo.h
@@ -29,41 +29,61 @@ public:
 
   /// getReturnSaveOffset - Return the previous frame offset to save the
   /// return address.
-  static unsigned getReturnSaveOffset(bool LP64) {
-    return LP64 ? 16 : 8;
+  static unsigned getReturnSaveOffset(bool LP64, bool isMacho) {
+    if (isMacho)
+      return LP64 ? 16 : 8;
+    // For ELF ABI:
+    return LP64 ? 8 : 4;
   }
 
   /// getFramePointerSaveOffset - Return the previous frame offset to save the
   /// frame pointer.
-  static unsigned getFramePointerSaveOffset(bool LP64) {
+  static unsigned getFramePointerSaveOffset(bool LP64, bool isMacho) {
+    // For MachO ABI:
     // Use the TOC save slot in the PowerPC linkage area for saving the frame
     // pointer (if needed.)  LLVM does not generate code that uses the TOC (R2
     // is treated as a caller saved register.)
-    return LP64 ? 40 : 20;
+    if (isMacho)
+      return LP64 ? 40 : 20;
+    
+    // For ELF ABI:
+    // Save it right before the link register
+    return LP64 ? -8 : -4;
   }
   
   /// getLinkageSize - Return the size of the PowerPC ABI linkage area.
   ///
-  static unsigned getLinkageSize(bool LP64) {
-    return 6 * (LP64 ? 8 : 4);
+  static unsigned getLinkageSize(bool LP64, bool isMacho) {
+    if (isMacho)
+      return 6 * (LP64 ? 8 : 4);
+    
+    // For ELF ABI:
+    return LP64 ? 16 : 8;
   }
 
   /// getMinCallArgumentsSize - Return the size of the minium PowerPC ABI
   /// argument area.
-  static unsigned getMinCallArgumentsSize(bool LP64) {
-   // The prolog code of the callee may store up to 8 GPR argument registers to
-   // the stack, allowing va_start to index over them in memory if its varargs.
-   // Because we cannot tell if this is needed on the caller side, we have to
-   // conservatively assume that it is needed.  As such, make sure we have at
-   // least enough stack space for the caller to store the 8 GPRs.
-    return 8 * (LP64 ? 8 : 4);
+  static unsigned getMinCallArgumentsSize(bool LP64, bool isMacho) {
+    // For Macho ABI:
+    // The prolog code of the callee may store up to 8 GPR argument registers to
+    // the stack, allowing va_start to index over them in memory if its varargs.
+    // Because we cannot tell if this is needed on the caller side, we have to
+    // conservatively assume that it is needed.  As such, make sure we have at
+    // least enough stack space for the caller to store the 8 GPRs.
+    if (isMacho)
+      return 8 * (LP64 ? 8 : 4);
+    
+    // For Linux ABI:
+    // There is no default stack allocated for the 8 first GPR arguments.
+    return 0;
   }
 
   /// getMinCallFrameSize - Return the minimum size a call frame can be using
   /// the PowerPC ABI.
-  static unsigned getMinCallFrameSize(bool LP64) {
+  static unsigned getMinCallFrameSize(bool LP64, bool isMacho) {
     // The call frame needs to be at least big enough for linkage and 8 args.
-    return getLinkageSize(LP64) + getMinCallArgumentsSize(LP64);
+    return getLinkageSize(LP64, isMacho) +
+           getMinCallArgumentsSize(LP64, isMacho);
   }
   
 };