[GISel]: Fix incorrect IRTranslation while translating null pointer types

https://reviews.llvm.org/D44762

Currently IRTranslator produces
%vreg17<def>(p0) = G_CONSTANT 0;

instead we should build
%vreg16(s64) = G_CONSTANT 0
%vreg17(p0) = G_INTTOPTR %vreg16

reviewed by @aemerson.

llvm-svn: 328218
diff --git a/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp b/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
index 7fb82153..b0a40f8 100644
--- a/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
@@ -1195,9 +1195,15 @@
     EntryBuilder.buildFConstant(Reg, *CF);
   else if (isa<UndefValue>(C))
     EntryBuilder.buildUndef(Reg);
-  else if (isa<ConstantPointerNull>(C))
-    EntryBuilder.buildConstant(Reg, 0);
-  else if (auto GV = dyn_cast<GlobalValue>(&C))
+  else if (isa<ConstantPointerNull>(C)) {
+    // As we are trying to build a constant val of 0 into a pointer,
+    // insert a cast to make them correct with respect to types.
+    unsigned NullSize = DL->getTypeSizeInBits(C.getType());
+    auto *ZeroTy = Type::getIntNTy(C.getContext(), NullSize);
+    auto *ZeroVal = ConstantInt::get(ZeroTy, 0);
+    unsigned ZeroReg = getOrCreateVReg(*ZeroVal);
+    EntryBuilder.buildCast(Reg, ZeroReg);
+  } else if (auto GV = dyn_cast<GlobalValue>(&C))
     EntryBuilder.buildGlobalValue(Reg, GV);
   else if (auto CAZ = dyn_cast<ConstantAggregateZero>(&C)) {
     if (!CAZ->getType()->isVectorTy())
diff --git a/llvm/test/CodeGen/AArch64/GlobalISel/arm64-fallback.ll b/llvm/test/CodeGen/AArch64/GlobalISel/arm64-fallback.ll
index 70d355b..59b56ac 100644
--- a/llvm/test/CodeGen/AArch64/GlobalISel/arm64-fallback.ll
+++ b/llvm/test/CodeGen/AArch64/GlobalISel/arm64-fallback.ll
@@ -169,7 +169,7 @@
   br label %block
 }
 
-; FALLBACK-WITH-REPORT-ERR: remark: <unknown>:0:0: unable to legalize instruction: G_STORE %0:_(<2 x p0>), %4:_(p0) :: (store 16 into `<2 x i16*>* undef`) (in function: vector_of_pointers_insertelement)
+; FALLBACK-WITH-REPORT-ERR: remark: <unknown>:0:0: unable to legalize instruction: G_STORE %0:_(<2 x p0>), %5:_(p0) :: (store 16 into `<2 x i16*>* undef`) (in function: vector_of_pointers_insertelement)
 ; FALLBACK-WITH-REPORT-ERR: warning: Instruction selection used fallback path for vector_of_pointers_insertelement
 ; FALLBACK-WITH-REPORT-OUT-LABEL: vector_of_pointers_insertelement:
 define void @vector_of_pointers_insertelement() {
diff --git a/llvm/test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll b/llvm/test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll
index 077be5e..da5d814 100644
--- a/llvm/test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll
+++ b/llvm/test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll
@@ -700,7 +700,8 @@
 }
 
 ; CHECK-LABEL: name: test_constant_null
-; CHECK: [[NULL:%[0-9]+]]:_(p0) = G_CONSTANT i64 0
+; CHECK: [[ZERO:%[0-9]+]]:_(s64) = G_CONSTANT i64 0
+; CHECK: [[NULL:%[0-9]+]]:_(p0) = G_INTTOPTR [[ZERO]]
 ; CHECK: $x0 = COPY [[NULL]]
 define i8* @test_constant_null() {
   ret i8* null
diff --git a/llvm/test/CodeGen/AArch64/GlobalISel/call-translator.ll b/llvm/test/CodeGen/AArch64/GlobalISel/call-translator.ll
index bf29fc0..a4c8ba9 100644
--- a/llvm/test/CodeGen/AArch64/GlobalISel/call-translator.ll
+++ b/llvm/test/CodeGen/AArch64/GlobalISel/call-translator.ll
@@ -187,7 +187,8 @@
 ; CHECK-LABEL: name: test_call_stack
 ; CHECK: [[C42:%[0-9]+]]:_(s64) = G_CONSTANT i64 42
 ; CHECK: [[C12:%[0-9]+]]:_(s64) = G_CONSTANT i64 12
-; CHECK: [[PTR:%[0-9]+]]:_(p0) = G_CONSTANT i64 0
+; CHECK: [[ZERO:%[0-9]+]]:_(s64) = G_CONSTANT i64 0
+; CHECK: [[PTR:%[0-9]+]]:_(p0) = G_INTTOPTR [[ZERO]]
 ; CHECK: ADJCALLSTACKDOWN 24, 0, implicit-def $sp, implicit $sp
 ; CHECK: [[SP:%[0-9]+]]:_(p0) = COPY $sp
 ; CHECK: [[C42_OFFS:%[0-9]+]]:_(s64) = G_CONSTANT i64 0
diff --git a/llvm/test/CodeGen/AArch64/GlobalISel/irtranslator-exceptions.ll b/llvm/test/CodeGen/AArch64/GlobalISel/irtranslator-exceptions.ll
index 3aa8717..be18a5d 100644
--- a/llvm/test/CodeGen/AArch64/GlobalISel/irtranslator-exceptions.ll
+++ b/llvm/test/CodeGen/AArch64/GlobalISel/irtranslator-exceptions.ll
@@ -64,7 +64,8 @@
 
 ; CHECK-LABEL: name: test_invoke_varargs
 
-; CHECK: [[NULL:%[0-9]+]]:_(p0) = G_CONSTANT i64 0
+; CHECK: [[ZERO:%[0-9]+]]:_(s64) = G_CONSTANT i64 0
+; CHECK: [[NULL:%[0-9]+]]:_(p0) = G_INTTOPTR [[ZERO]]
 ; CHECK: [[ANSWER:%[0-9]+]]:_(s32) = G_CONSTANT i32 42
 ; CHECK: [[ONE:%[0-9]+]]:_(s32) = G_FCONSTANT float 1.0
 
diff --git a/llvm/test/CodeGen/AArch64/GlobalISel/translate-gep.ll b/llvm/test/CodeGen/AArch64/GlobalISel/translate-gep.ll
index ae9251a..a306cd0 100644
--- a/llvm/test/CodeGen/AArch64/GlobalISel/translate-gep.ll
+++ b/llvm/test/CodeGen/AArch64/GlobalISel/translate-gep.ll
@@ -6,7 +6,8 @@
 define i8*  @translate_element_size1(i64 %arg) {
 ; CHECK-LABEL: name: translate_element_size1
 ; CHECK: [[OFFSET:%[0-9]+]]:_(s64) = COPY $x0
-; CHECK: [[BASE:%[0-9]+]]:_(p0) = G_CONSTANT i64 0
+; CHECK: [[ZERO:%[0-9]+]]:_(s64) = G_CONSTANT i64 0
+; CHECK: [[BASE:%[0-9]+]]:_(p0) = G_INTTOPTR [[ZERO]]
 ; CHECK: [[GEP:%[0-9]+]]:_(p0) = G_GEP [[BASE]], [[OFFSET]]
   %tmp = getelementptr i8, i8* null, i64 %arg
   ret i8* %tmp