[SVE] Pass Scalable argument to VectorType::get in Bitcode Reader

[ctetreau]

Summary

• Pass the Scalability test to VectorType::get in order to be

able to deserialize bitcode that contains scalable vector operations

[ctetreau]

llvm/lib/Bitcode/Reader/BitcodeReader.cpp

4175

This is the source of the bug from last patch. I passed the length of Vec1, not of the mask, which is not in line with the documented behavior of shufflevector or the original code.

[efriedma]

If you're reposting the "same" patch because it was reverted, usually you want to reopen the existing revision, rather than post a new one. (Phabricator should give you a "reopen" option for closed reviews.) That said, at this point, it's not worth going back to fix that; there wasn't any substantial discussion posted on D72792.

LGTM

[ctetreau]

This is a resubmission of https://reviews.llvm.org/D72792 having fixed the test failures.

llvm/lib/Bitcode/Reader/BitcodeReader.cpp

case bitc::CST_CODE_CE_GEP_WITH_INRANGE_INDEX: { // [ty, flags, n x
       break;
     }
     case bitc::CST_CODE_CE_SELECT: {  // CE_SELECT: [opval#, opval#, opval#]
       if (Record.size() < 3)
         return error("Invalid record");
 
       Type *SelectorTy = Type::getInt1Ty(Context);
 
-      // The selector might be an i1 or an <n x i1>
+      // The selector might be an i1, an <n x i1>, or a <vscale x n x i1>
       // Get the type from the ValueList before getting a forward ref.
       if (VectorType *VTy = dyn_cast<VectorType>(CurTy))
         if (Value *V = ValueList[Record[0]])
           if (SelectorTy != V->getType())
-            SelectorTy = VectorType::get(SelectorTy, VTy->getNumElements());
+            SelectorTy = VectorType::get(SelectorTy,
+                                         VTy->getElementCount());
 
       V = ConstantExpr::getSelect(ValueList.getConstantFwdRef(Record[0],
                                                               SelectorTy),
                                   ValueList.getConstantFwdRef(Record[1],CurTy),
                                   ValueList.getConstantFwdRef(Record[2],CurTy));
       break;
     }
     case bitc::CST_CODE_CE_EXTRACTELT
while (true) {
     }
     case bitc::CST_CODE_CE_SHUFFLEVEC: { // CE_SHUFFLEVEC: [opval, opval, opval]
       VectorType *OpTy = dyn_cast<VectorType>(CurTy);
       if (Record.size() < 3 || !OpTy)
         return error("Invalid record");
       Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
       Constant *Op1 = ValueList.getConstantFwdRef(Record[1], OpTy);
       Type *ShufTy = VectorType::get(Type::getInt32Ty(Context),
-                                                 OpTy->getNumElements());
+                                     OpTy->getElementCount());
       Constant *Op2 = ValueList.getConstantFwdRef(Record[2], ShufTy);
       V = ConstantExpr::getShuffleVector(Op0, Op1, Op2);
       break;
     }
     case bitc::CST_CODE_CE_SHUFVEC_EX: { // [opty, opval, opval, opval]
       VectorType *RTy = dyn_cast<VectorType>(CurTy);
       VectorType *OpTy =
         dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
       if (Record.size() < 4 || !RTy || !OpTy)
         return error("Invalid record");
       Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
       Constant *Op1 = ValueList.getConstantFwdRef(Record[2], OpTy);
       Type *ShufTy = VectorType::get(Type::getInt32Ty(Context),
-                                                 RTy->getNumElements());
+                                     RTy->getElementCount());
       Constant *Op2 = ValueList.getConstantFwdRef(Record[3], ShufTy);
       V = ConstantExpr::getShuffleVector(Op0, Op1, Op2);
       break;
     }
     case bitc::CST_CODE_CE_CMP: {     // CE_CMP: [opty, opval, opval, pred]
       if (Record.size() < 4)
         return error("Invalid record");
       Type *OpTy = getTypeByID(Record[0]);
case bitc::FUNC_CODE_INST_SHUFFLEVEC: {// SHUFFLEVEC: [opval,ty,opval,opval]
       if (getValueTypePair(Record, OpNum, NextValueNo, Vec1, &FullTy) ||
           popValue(Record, OpNum, NextValueNo, Vec1->getType(), Vec2))
         return error("Invalid record");
 
       if (getValueTypePair(Record, OpNum, NextValueNo, Mask))
         return error("Invalid record");
       if (!Vec1->getType()->isVectorTy() || !Vec2->getType()->isVectorTy())
         return error("Invalid type for value");
+
       I = new ShuffleVectorInst(Vec1, Vec2, Mask);
       FullTy = VectorType::get(FullTy->getVectorElementType(),
-                               Mask->getType()->getVectorNumElements());
+                               Mask->getType()->getVectorElementCount());
       InstructionList.push_back(I);
       break;
     }
 
     case bitc::FUNC_CODE_INST_CMP:   // CMP: [opty, opval, opval, pred]
       // Old form of ICmp/FCmp returning bool
       // Existed to differentiate between icmp/fcmp and vicmp/vfcmp which were
       // both legal on vectors but had different behaviour.

llvm/test/Bitcode/vscale-round-trip.ll

+; RUN: llvm-as < %s | llvm-dis | FileCheck %s
+
+target datalayout = "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128"
+target triple = "aarch64"
+
+@important_val = extern_weak dso_local global i32, align 4
+
+; CHECK-LABEL: define <vscale x 4 x i32> @const_shufflevector(
+; CHECK: <vscale x 4 x i32> shufflevector (<vscale x 4 x i32>
+
+define <vscale x 4 x i32> @const_shufflevector() {
+  ret <vscale x 4 x i32> shufflevector (<vscale x 4 x i32> zeroinitializer,
+                                        <vscale x 4 x i32> undef,
+                                        <vscale x 4 x i32> zeroinitializer)
+}
+
+; CHECK-LABEL: define <vscale x 4 x i32> @const_shufflevector_ex()
+; CHECK: <vscale x 4 x i32> shufflevector (<vscale x 2 x i32>
+
+define <vscale x 4 x i32> @const_shufflevector_ex() {
+  ret <vscale x 4 x i32> shufflevector (<vscale x 2 x i32> zeroinitializer,
+                                        <vscale x 2 x i32> undef,
+                                        <vscale x 4 x i32> zeroinitializer)
+}
+
+; CHECK-LABEL: define <vscale x 4 x i32> @non_const_shufflevector(
+; CHECK: %res = shufflevector <vscale x 4 x i32>
+
+define <vscale x 4 x i32> @non_const_shufflevector(<vscale x 4 x i32> %lhs,
+                                                   <vscale x 4 x i32> %rhs) {
+  %res = shufflevector <vscale x 4 x i32> %lhs,
+                       <vscale x 4 x i32> %rhs,
+                       <vscale x 4 x i32> zeroinitializer
+
+  ret <vscale x 4 x i32> %res
+}
+
+; CHECK-LABEL: define <vscale x 4 x i32> @const_select()
+; CHECK: <vscale x 4 x i32> select (<vscale x 4 x i1>
+
+define <vscale x 4 x i32> @const_select() {
+  ret <vscale x 4 x i32> select
+    (<vscale x 4 x i1> insertelement
+      (<vscale x 4 x i1> undef,
+       i1 icmp ne (i32* @important_val, i32* null),
+       i32 0),
+     <vscale x 4 x i32> zeroinitializer,
+     <vscale x 4 x i32> insertelement (<vscale x 4 x i32> undef, i32 1, i32 0))
+}