From: Hal Finkel <hfinkel@anl.gov>
Date: Sat, 24 Mar 2012 03:53:55 +0000 (+0000)
Subject: Fix small-integer VAARG on SVR4 ABI PPC64.
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=179a4ddd1fe52a3698a4b87e024250ed508df77a;p=oota-llvm.git

Fix small-integer VAARG on SVR4 ABI PPC64.

The PPC64 SVR4 ABI requires integer stack arguments, and thus the var. args., that
are smaller than 64 bits be zero extended to 64 bits.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153373 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Target/PowerPC/PPCISelLowering.cpp b/lib/Target/PowerPC/PPCISelLowering.cpp
index 85b5bc10e22..a5dbef7741a 100644
--- a/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -226,11 +226,23 @@ PPCTargetLowering::PPCTargetLowering(PPCTargetMachine &TM)
   // VASTART needs to be custom lowered to use the VarArgsFrameIndex
   setOperationAction(ISD::VASTART           , MVT::Other, Custom);
 
-  // VAARG is custom lowered with the 32-bit SVR4 ABI.
-  if (TM.getSubtarget<PPCSubtarget>().isSVR4ABI()
-      && !TM.getSubtarget<PPCSubtarget>().isPPC64()) {
-    setOperationAction(ISD::VAARG, MVT::Other, Custom);
-    setOperationAction(ISD::VAARG, MVT::i64, Custom);
+  if (TM.getSubtarget<PPCSubtarget>().isSVR4ABI()) {
+    if (TM.getSubtarget<PPCSubtarget>().isPPC64()) {
+      // VAARG always uses double-word chunks, so promote anything smaller.
+      setOperationAction(ISD::VAARG, MVT::i1, Promote);
+      AddPromotedToType (ISD::VAARG, MVT::i1, MVT::i64);
+      setOperationAction(ISD::VAARG, MVT::i8, Promote);
+      AddPromotedToType (ISD::VAARG, MVT::i8, MVT::i64);
+      setOperationAction(ISD::VAARG, MVT::i16, Promote);
+      AddPromotedToType (ISD::VAARG, MVT::i16, MVT::i64);
+      setOperationAction(ISD::VAARG, MVT::i32, Promote);
+      AddPromotedToType (ISD::VAARG, MVT::i32, MVT::i64);
+      setOperationAction(ISD::VAARG, MVT::Other, Expand);
+    } else {
+      // VAARG is custom lowered with the 32-bit SVR4 ABI.
+      setOperationAction(ISD::VAARG, MVT::Other, Custom);
+      setOperationAction(ISD::VAARG, MVT::i64, Custom);
+    }
   } else
     setOperationAction(ISD::VAARG, MVT::Other, Expand);
 
diff --git a/test/CodeGen/PowerPC/ppc64-vaarg-int.ll b/test/CodeGen/PowerPC/ppc64-vaarg-int.ll
new file mode 100644
index 00000000000..5a63b01badc
--- /dev/null
+++ b/test/CodeGen/PowerPC/ppc64-vaarg-int.ll
@@ -0,0 +1,20 @@
+target datalayout = "E-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v128:128:128-n32:64"
+target triple = "powerpc64-unknown-linux-gnu"
+; RUN: llc < %s | FileCheck %s
+
+define i32 @intvaarg(i32 %a, ...) nounwind {
+entry:
+  %va = alloca i8*, align 8
+  %va1 = bitcast i8** %va to i8*
+  call void @llvm.va_start(i8* %va1)
+  %0 = va_arg i8** %va, i32
+  %sub = sub nsw i32 %a, %0
+  ret i32 %sub
+}
+
+declare void @llvm.va_start(i8*) nounwind
+
+; CHECK: @intvaarg
+; Make sure that the va pointer is incremented by 8 (not 4).
+; CHECK: addi{{.*}}, 8
+