[MIR] Print target-specific constant pools

This should enable us to test the generation of target-specific constant
pools, e.g. for ARM:

constants:
 - id:              0
   value:           'g(GOT_PREL)-(LPC0+8-.)'
   alignment:       4
   isTargetSpecific: true

I intend to use this to test PIC support in GlobalISel for ARM.

This is difficult to test outside of that context, since the existing
MIR tests usually rely on parser support as well, and that seems a bit
trickier to add. We could try to add a unit test, but the setup for that
seems rather convoluted and overkill.

We do test however that the parser reports a nice error when
encountering a target-specific constant pool.

Differential Revision: https://reviews.llvm.org/D36092

llvm-svn: 309806

5 files changed, 50 insertions, 7 deletions

diff --git a/llvm/include/llvm/CodeGen/MIRYamlMapping.h b/llvm/include/llvm/CodeGen/MIRYamlMapping.h
index cbd94f1c417..8e2c6149a82 100644
--- a/llvm/include/llvm/CodeGen/MIRYamlMapping.h
+++ b/llvm/include/llvm/CodeGen/MIRYamlMapping.h
@@ -310,9 +310,11 @@ struct MachineConstantPoolValue {
   UnsignedValue ID;
   StringValue Value;
   unsigned Alignment = 0;
+  bool IsTargetSpecific = false;
   bool operator==(const MachineConstantPoolValue &Other) const {
     return ID == Other.ID && Value == Other.Value &&
-           Alignment == Other.Alignment;
+           Alignment == Other.Alignment &&
+           IsTargetSpecific == Other.IsTargetSpecific;
   }
 };
 
@@ -321,6 +323,7 @@ template <> struct MappingTraits<MachineConstantPoolValue> {
     YamlIO.mapRequired("id", Constant.ID);
     YamlIO.mapOptional("value", Constant.Value, StringValue());
     YamlIO.mapOptional("alignment", Constant.Alignment, (unsigned)0);
+    YamlIO.mapOptional("isTargetSpecific", Constant.IsTargetSpecific, false);
   }
 };
 
diff --git a/llvm/lib/CodeGen/MIRParser/MIRParser.cpp b/llvm/lib/CodeGen/MIRParser/MIRParser.cpp
index d0b46c4668b..5df8dbce36a 100644
--- a/llvm/lib/CodeGen/MIRParser/MIRParser.cpp
+++ b/llvm/lib/CodeGen/MIRParser/MIRParser.cpp
@@ -719,6 +719,10 @@ bool MIRParserImpl::initializeConstantPool(PerFunctionMIParsingState &PFS,
   const auto &M = *MF.getFunction()->getParent();
   SMDiagnostic Error;
   for (const auto &YamlConstant : YamlMF.Constants) {
+    if (YamlConstant.IsTargetSpecific)
+      // FIXME: Support target-specific constant pools
+      return error(YamlConstant.Value.SourceRange.Start,
+                   "Can't parse target-specific constant pool entries yet");
     const Constant *Value = dyn_cast_or_null<Constant>(
         parseConstantValue(YamlConstant.Value.Value, Error, M));
     if (!Value)
diff --git a/llvm/lib/CodeGen/MIRPrinter.cpp b/llvm/lib/CodeGen/MIRPrinter.cpp
index b9281b1e5e1..db9ccef8a36 100644
--- a/llvm/lib/CodeGen/MIRPrinter.cpp
+++ b/llvm/lib/CodeGen/MIRPrinter.cpp
@@ -458,17 +458,20 @@ void MIRPrinter::convert(yaml::MachineFunction &MF,
                          const MachineConstantPool &ConstantPool) {
   unsigned ID = 0;
   for (const MachineConstantPoolEntry &Constant : ConstantPool.getConstants()) {
-    // TODO: Serialize target specific constant pool entries.
-    if (Constant.isMachineConstantPoolEntry())
-      llvm_unreachable("Can't print target specific constant pool entries yet");
-
-    yaml::MachineConstantPoolValue YamlConstant;
     std::string Str;
     raw_string_ostream StrOS(Str);
-    Constant.Val.ConstVal->printAsOperand(StrOS);
+    if (Constant.isMachineConstantPoolEntry()) {
+      Constant.Val.MachineCPVal->print(StrOS);
+    } else {
+      Constant.Val.ConstVal->printAsOperand(StrOS);
+    }
+
+    yaml::MachineConstantPoolValue YamlConstant;
     YamlConstant.ID = ID++;
     YamlConstant.Value = StrOS.str();
     YamlConstant.Alignment = Constant.getAlignment();
+    YamlConstant.IsTargetSpecific = Constant.isMachineConstantPoolEntry();
+
     MF.Constants.push_back(YamlConstant);
   }
 }
diff --git a/llvm/test/CodeGen/MIR/ARM/target-constant-pools-error.mir b/llvm/test/CodeGen/MIR/ARM/target-constant-pools-error.mir
new file mode 100644
index 00000000000..4fc7ea1f3cd
--- /dev/null
+++ b/llvm/test/CodeGen/MIR/ARM/target-constant-pools-error.mir
@@ -0,0 +1,27 @@
+# RUN: not llc -mtriple arm-unknown -run-pass none -o /dev/null %s 2>&1 | FileCheck %s
+--- |
+  target datalayout = "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64"
+
+  @g = private global i32 4
+  define void @target_constant_pool() { ret void }
+...
+---
+name:            target_constant_pool
+tracksRegLiveness: true
+registers:
+  - { id: 0, class: gpr, preferred-register: '' }
+  - { id: 1, class: gpr, preferred-register: '' }
+constants:
+  - id:              0
+  # CHECK: [[@LINE+1]]:22: Can't parse target-specific constant pool entries yet
+    value:           'g-(LPC0+8)'
+    alignment:       4
+    isTargetSpecific: true
+body:             |
+  bb.0.entry:
+    %0 = LDRi12 %const.0, 0, 14, _ :: (load 4 from constant-pool)
+    %1 = PICLDR killed %0, 0, 14, _ :: (dereferenceable load 4 from @g)
+    %r0 = COPY %1
+    BX_RET 14, _, implicit %r0
+
+...
diff --git a/llvm/test/CodeGen/MIR/X86/constant-pool.mir b/llvm/test/CodeGen/MIR/X86/constant-pool.mir
index 3312e6f67bd..60e12d3ddcd 100644
--- a/llvm/test/CodeGen/MIR/X86/constant-pool.mir
+++ b/llvm/test/CodeGen/MIR/X86/constant-pool.mir
@@ -46,9 +46,11 @@
 # CHECK-NEXT: - id: 0
 # CHECK-NEXT:   value: 'double 3.250000e+00'
 # CHECK-NEXT:   alignment: 8
+# CHECK-NEXT:   isTargetSpecific: false
 # CHECK-NEXT: - id: 1
 # CHECK-NEXT:   value: 'float 6.250000e+00'
 # CHECK-NEXT:   alignment: 4
+# CHECK-NEXT:   isTargetSpecific: false
 name:            test
 constants:
   - id:          0
@@ -74,9 +76,11 @@ body: |
 # CHECK-NEXT: - id: 0
 # CHECK-NEXT:   value: 'double 3.250000e+00'
 # CHECK-NEXT:   alignment: 8
+# CHECK-NEXT:   isTargetSpecific: false
 # CHECK-NEXT: - id: 1
 # CHECK-NEXT:   value: 'float 6.250000e+00'
 # CHECK-NEXT:   alignment: 4
+# CHECK-NEXT:   isTargetSpecific: false
 name:            test2
 constants:
   - id:          0
@@ -98,9 +102,11 @@ body: |
 # CHECK-NEXT: - id: 0
 # CHECK-NEXT:   value: 'double 3.250000e+00'
 # CHECK-NEXT:   alignment: 128
+# CHECK-NEXT:   isTargetSpecific: false
 # CHECK-NEXT: - id: 1
 # CHECK-NEXT:   value: 'float 6.250000e+00'
 # CHECK-NEXT:   alignment: 1
+# CHECK-NEXT:   isTargetSpecific: false
 name:            test3
 constants:
   - id:          0