Merging r354846:

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r354846 | djg | 2019-02-25 21:20:19 -0800 (Mon, 25 Feb 2019) | 12 lines

[WebAssembly] Properly align fp128 arguments in outgoing varargs arguments

For outgoing varargs arguments, it's necessary to check the OrigAlign field
of the corresponding OutputArg entry to determine argument alignment, rather
than just computing an alignment from the argument value type. This is
because types like fp128 are split into multiple argument values, with
narrower types that don't reflect the ABI alignment of the full fp128.

This fixes the printf("printfL: %4.*Lf\n", 2, lval); testcase.

Differential Revision: https://reviews.llvm.org/D58656

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_80@360826 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp b/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
index 003848e3422796850c7ea19a43fa9b7a3a036779..f7f29d85cbb270d72bde85b84e242a2a75274bcf 100644 (file)
--- a/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
+++ b/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
@@ -669,13 +669,16 @@ WebAssemblyTargetLowering::LowerCall(CallLoweringInfo &CLI,
   if (IsVarArg) {
     // Outgoing non-fixed arguments are placed in a buffer. First
     // compute their offsets and the total amount of buffer space needed.
-    for (SDValue Arg :
-         make_range(OutVals.begin() + NumFixedArgs, OutVals.end())) {
+    for (unsigned I = NumFixedArgs; I < Outs.size(); ++I) {
+      const ISD::OutputArg &Out = Outs[I];
+      SDValue &Arg = OutVals[I];
       EVT VT = Arg.getValueType();
       assert(VT != MVT::iPTR && "Legalized args should be concrete");
       Type *Ty = VT.getTypeForEVT(*DAG.getContext());
+      unsigned Align = std::max(Out.Flags.getOrigAlign(),
+                                Layout.getABITypeAlignment(Ty));
       unsigned Offset = CCInfo.AllocateStack(Layout.getTypeAllocSize(Ty),
-                                             Layout.getABITypeAlignment(Ty));
+                                             Align);
       CCInfo.addLoc(CCValAssign::getMem(ArgLocs.size(), VT.getSimpleVT(),
                                         Offset, VT.getSimpleVT(),
                                         CCValAssign::Full));

diff --git a/test/CodeGen/WebAssembly/varargs.ll b/test/CodeGen/WebAssembly/varargs.ll
index 1a73716c2a67cb6cde14cac78cc25b4ca3d971e0..5a8df4cd2fec4b7f69400f4d2b5a375434a2daa2 100644 (file)
--- a/test/CodeGen/WebAssembly/varargs.ll
+++ b/test/CodeGen/WebAssembly/varargs.ll
@@ -163,6 +163,32 @@ define void @nonlegal_fixed(fp128 %x, ...) nounwind {
   ret void
 }
 
+; Test that an fp128 argument is properly aligned and allocated
+; within a vararg buffer.
+
+; CHECK-LABEL: call_fp128_alignment:
+; CHECK:      global.get      $push7=, __stack_pointer
+; CHECK-NEXT: i32.const       $push8=, 32
+; CHECK-NEXT: i32.sub         $push12=, $pop7, $pop8
+; CHECK-NEXT: local.tee       $push11=, $1=, $pop12
+; CHECK-NEXT: global.set      __stack_pointer@GLOBAL, $pop11
+; CHECK-NEXT: i32.const       $push0=, 24
+; CHECK-NEXT: i32.add         $push1=, $1, $pop0
+; CHECK-NEXT: i64.const       $push2=, -9223372036854775808
+; CHECK-NEXT: i64.store       0($pop1), $pop2
+; CHECK-NEXT: i32.const       $push3=, 16
+; CHECK-NEXT: i32.add         $push4=, $1, $pop3
+; CHECK-NEXT: i64.const       $push5=, 1
+; CHECK-NEXT: i64.store       0($pop4), $pop5
+; CHECK-NEXT: i32.const       $push6=, 7
+; CHECK-NEXT: i32.store       0($1), $pop6
+; CHECK-NEXT: call            callee@FUNCTION, $1
+define void @call_fp128_alignment(i8* %p) {
+entry:
+  call void (...) @callee(i8 7, fp128 0xL00000000000000018000000000000000)
+  ret void
+}
+
 declare void @llvm.va_start(i8*)
 declare void @llvm.va_end(i8*)
 declare void @llvm.va_copy(i8*, i8*)