[PATCH] D133338: [clang][PowerPC] PPC64 VAArg use coerced integer type for direct aggregate fits in register

[Ting Wang via Phabricator via cfe-commits]

tingwang updated this revision to Diff 466992.
tingwang added a comment.

Address comment: move TODO close to PPC64 specific case.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D133338/new/

https://reviews.llvm.org/D133338

Files:
  clang/lib/CodeGen/TargetInfo.cpp
  clang/test/CodeGen/PowerPC/ppc64-align-struct.c


Index: clang/test/CodeGen/PowerPC/ppc64-align-struct.c
===================================================================
--- clang/test/CodeGen/PowerPC/ppc64-align-struct.c
+++ clang/test/CodeGen/PowerPC/ppc64-align-struct.c
@@ -117,12 +117,12 @@
   return y;
 }
 
-// Error pattern will be fixed in https://reviews.llvm.org/D133338
 // CHECK: define{{.*}} void @test8va(ptr noalias sret(%struct.test8) align 1 %[[AGG_RESULT:.*]], i32 noundef signext %x, ...)
 // CHECK: %[[CUR:[^ ]+]] = load ptr, ptr %ap
 // CHECK: %[[NEXT:[^ ]+]] = getelementptr inbounds i8, ptr %[[CUR]], i64 8
 // CHECK: store ptr %[[NEXT]], ptr %ap
-// CHECK: call void @llvm.memcpy.p0.p0.i64(ptr align 1 %[[AGG_RESULT]], ptr align 8 %[[CUR]], i64 1, i1 false)
+// CHECK: [[T0:%.*]] = getelementptr inbounds i8, ptr %[[CUR]], i64 7
+// CHECK: call void @llvm.memcpy.p0.p0.i64(ptr align 1 %[[AGG_RESULT]], ptr align 1 [[T0]], i64 1, i1 false)
 struct test8 test8va (int x, ...)
 {
   struct test8 y;
Index: clang/lib/CodeGen/TargetInfo.cpp
===================================================================
--- clang/lib/CodeGen/TargetInfo.cpp
+++ clang/lib/CodeGen/TargetInfo.cpp
@@ -322,13 +322,17 @@
 ///   leaving one or more empty slots behind as padding.  If this
 ///   is false, the returned address might be less-aligned than
 ///   DirectAlign.
+/// \param ForceRightAdjust - Default is false. On big-endian platform and
+///   if the argument is smaller than a slot, set this flag will force
+///   right-adjust the argument in its slot irrespective of the type.
 static Address emitVoidPtrDirectVAArg(CodeGenFunction &CGF,
                                       Address VAListAddr,
                                       llvm::Type *DirectTy,
                                       CharUnits DirectSize,
                                       CharUnits DirectAlign,
                                       CharUnits SlotSize,
-                                      bool AllowHigherAlign) {
+                                      bool AllowHigherAlign,
+                                      bool ForceRightAdjust = false) {
   // Cast the element type to i8* if necessary.  Some platforms define
   // va_list as a struct containing an i8* instead of just an i8*.
   if (VAListAddr.getElementType() != CGF.Int8PtrTy)
@@ -354,7 +358,7 @@
   // If the argument is smaller than a slot, and this is a big-endian
   // target, the argument will be right-adjusted in its slot.
   if (DirectSize < SlotSize && CGF.CGM.getDataLayout().isBigEndian() &&
-      !DirectTy->isStructTy()) {
+      (!DirectTy->isStructTy() || ForceRightAdjust)) {
     Addr = CGF.Builder.CreateConstInBoundsByteGEP(Addr, SlotSize - DirectSize);
   }
 
@@ -375,11 +379,15 @@
 ///   an argument type with an alignment greater than the slot size
 ///   will be emitted on a higher-alignment address, potentially
 ///   leaving one or more empty slots behind as padding.
+/// \param ForceRightAdjust - Default is false. On big-endian platform and
+///   if the argument is smaller than a slot, set this flag will force
+///   right-adjust the argument in its slot irrespective of the type.
 static Address emitVoidPtrVAArg(CodeGenFunction &CGF, Address VAListAddr,
                                 QualType ValueTy, bool IsIndirect,
                                 TypeInfoChars ValueInfo,
                                 CharUnits SlotSizeAndAlign,
-                                bool AllowHigherAlign) {
+                                bool AllowHigherAlign,
+                                bool ForceRightAdjust = false) {
   // The size and alignment of the value that was passed directly.
   CharUnits DirectSize, DirectAlign;
   if (IsIndirect) {
@@ -395,9 +403,9 @@
   if (IsIndirect)
     DirectTy = DirectTy->getPointerTo(0);
 
-  Address Addr =
-      emitVoidPtrDirectVAArg(CGF, VAListAddr, DirectTy, DirectSize, DirectAlign,
-                             SlotSizeAndAlign, AllowHigherAlign);
+  Address Addr = emitVoidPtrDirectVAArg(CGF, VAListAddr, DirectTy, DirectSize,
+                                        DirectAlign, SlotSizeAndAlign,
+                                        AllowHigherAlign, ForceRightAdjust);
 
   if (IsIndirect) {
     Addr = Address(CGF.Builder.CreateLoad(Addr), ElementTy, ValueInfo.Align);
@@ -5451,8 +5459,11 @@
   }
 
   // Otherwise, just use the general rule.
-  return emitVoidPtrVAArg(CGF, VAListAddr, Ty, /*Indirect*/ false,
-                          TypeInfo, SlotSize, /*AllowHigher*/ true);
+  // TODO: a better approach may refer to SystemZABI use same logic for caller
+  // and callee to deduce the adjustment, then get rid of ForceRightAdjust.
+  return emitVoidPtrVAArg(CGF, VAListAddr, Ty, /*Indirect*/ false, TypeInfo,
+                          SlotSize, /*AllowHigher*/ true,
+                          /*ForceRightAdjust*/ true);
 }
 
 bool


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