This fixes functions like

void f (int a1, int a2, int a3, int a4, int a5,...)

In ARMTargetLowering::LowerFormalArguments if the function has 4 or
more regular arguments we used to set VarArgsFrameIndex using an
offset of 0, which is only correct if the function has exactly 4
regular arguments.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85590 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index 773166a4682c3ea88801590d68e54084b10a292c..a76729c5f8b5da035aa1c11fb0121bf82189f923 100644 (file)
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -1629,13 +1629,12 @@ ARMTargetLowering::LowerFormalArguments(SDValue Chain,
     unsigned Align = MF.getTarget().getFrameInfo()->getStackAlignment();
     unsigned VARegSize = (4 - NumGPRs) * 4;
     unsigned VARegSaveSize = (VARegSize + Align - 1) & ~(Align - 1);
-    unsigned ArgOffset = 0;
+    unsigned ArgOffset = CCInfo.getNextStackOffset();
     if (VARegSaveSize) {
       // If this function is vararg, store any remaining integer argument regs
       // to their spots on the stack so that they may be loaded by deferencing
       // the result of va_next.
       AFI->setVarArgsRegSaveSize(VARegSaveSize);
-      ArgOffset = CCInfo.getNextStackOffset();
       VarArgsFrameIndex = MFI->CreateFixedObject(VARegSaveSize, ArgOffset +
                                                  VARegSaveSize - VARegSize);
       SDValue FIN = DAG.getFrameIndex(VarArgsFrameIndex, getPointerTy());

diff --git a/test/CodeGen/ARM/2009-10-30.ll b/test/CodeGen/ARM/2009-10-30.ll
new file mode 100644 (file)
index 0000000..8256386
--- /dev/null
+++ b/test/CodeGen/ARM/2009-10-30.ll
@@ -0,0 +1,17 @@
+; RUN: llc < %s  -mtriple=arm-linux-gnueabi  | FileCheck %s
+; This test checks that the address of the varg arguments is correctly
+; computed when there are 5 or more regular arguments.
+
+define void @f(i32 %a1, i32 %a2, i32 %a3, i32 %a4, i32 %a5, ...) {
+entry:
+;CHECK: sub    sp, sp, #4
+;CHECK: add    r0, sp, #8
+;CHECK: str    r0, [sp], #+4
+;CHECK: bx     lr
+       %ap = alloca i8*, align 4
+       %ap1 = bitcast i8** %ap to i8*
+       call void @llvm.va_start(i8* %ap1)
+       ret void
+}
+
+declare void @llvm.va_start(i8*) nounwind