Support OpPtrEqual, OpPtrNotEqual and OpPtrDiff to compare pointers (#2482)

This addresses p.2 and p.3 of #2460

Original commit:
KhronosGroup/SPIRV-LLVM-Translator@4b4508438a6dfe5

Author: vmaksimo

llvm-spirv/lib/SPIRV/SPIRVReader.cpp

@@ -2165,6 +2165,28 @@ Value *SPIRVToLLVM::transValueWithoutDecoration(SPIRVValue *BV, Function *F,
     return mapValue(BV, V);
   }
 
+  case OpPtrEqual:
+  case OpPtrNotEqual: {
+    auto *BC = static_cast<SPIRVBinary *>(BV);
+    auto Ops = transValue(BC->getOperands(), F, BB);
+
+    IRBuilder<> Builder(BB);
+    Value *Op1 = Builder.CreatePtrToInt(Ops[0], Type::getInt64Ty(*Context));
+    Value *Op2 = Builder.CreatePtrToInt(Ops[1], Type::getInt64Ty(*Context));
+    CmpInst::Predicate P =
+        OC == OpPtrEqual ? ICmpInst::ICMP_EQ : ICmpInst::ICMP_NE;
+    Value *V = Builder.CreateICmp(P, Op1, Op2);
+    return mapValue(BV, V);
+  }
+
+  case OpPtrDiff: {
+    auto *BC = static_cast<SPIRVBinary *>(BV);
+    auto Ops = transValue(BC->getOperands(), F, BB);
+    IRBuilder<> Builder(BB);
+    Value *V = Builder.CreatePtrDiff(transType(BC->getType()), Ops[0], Ops[1]);
+    return mapValue(BV, V);
+  }
+
   case OpCompositeConstruct: {
     auto *CC = static_cast<SPIRVCompositeConstruct *>(BV);
     auto Constituents = transValue(CC->getOperands(), F, BB);

llvm-spirv/lib/SPIRV/libSPIRV/SPIRVInstruction.h

@@ -669,10 +669,21 @@ class SPIRVBinary : public SPIRVInstTemplateBase {
              "Invalid type for bitwise instruction");
       assert((Op1Ty->getIntegerBitWidth() == Op2Ty->getIntegerBitWidth()) &&
              "Inconsistent BitWidth");
+    } else if (isBinaryPtrOpCode(OpCode)) {
+      assert((Op1Ty->isTypePointer() && Op2Ty->isTypePointer()) &&
+             "Invalid types for PtrEqual, PtrNotEqual, or PtrDiff instruction");
+      assert(static_cast<SPIRVTypePointer *>(Op1Ty)->getElementType() ==
+                 static_cast<SPIRVTypePointer *>(Op2Ty)->getElementType() &&
+             "Invalid types for PtrEqual, PtrNotEqual, or PtrDiff instruction");
     } else {
       assert(0 && "Invalid op code!");
     }
   }
+  VersionNumber getRequiredSPIRVVersion() const override {
+    if (isBinaryPtrOpCode(OpCode))
+      return VersionNumber::SPIRV_1_4;
+    return VersionNumber::SPIRV_1_0;
+  }
 };
 
 template <Op OC>
@@ -707,6 +718,9 @@ _SPIRV_OP(BitwiseAnd)
 _SPIRV_OP(BitwiseOr)
 _SPIRV_OP(BitwiseXor)
 _SPIRV_OP(Dot)
+_SPIRV_OP(PtrEqual)
+_SPIRV_OP(PtrNotEqual)
+_SPIRV_OP(PtrDiff)
 #undef _SPIRV_OP
 
 template <Op TheOpCode> class SPIRVInstNoOperand : public SPIRVInstruction {

llvm-spirv/lib/SPIRV/libSPIRV/SPIRVOpCode.h

@@ -74,6 +74,10 @@ inline bool isBinaryOpCode(Op OpCode) {
          OpCode == OpDot || OpCode == OpIAddCarry || OpCode == OpISubBorrow;
 }
 
+inline bool isBinaryPtrOpCode(Op OpCode) {
+  return (unsigned)OpCode >= OpPtrEqual && (unsigned)OpCode <= OpPtrDiff;
+}
+
 inline bool isShiftOpCode(Op OpCode) {
   return (unsigned)OpCode >= OpShiftRightLogical &&
          (unsigned)OpCode <= OpShiftLeftLogical;

llvm-spirv/lib/SPIRV/libSPIRV/SPIRVOpCodeEnum.h

@@ -329,6 +329,9 @@ _SPIRV_OP(GroupNonUniformBitwiseXor, 361)
 _SPIRV_OP(GroupNonUniformLogicalAnd, 362)
 _SPIRV_OP(GroupNonUniformLogicalOr, 363)
 _SPIRV_OP(GroupNonUniformLogicalXor, 364)
+_SPIRV_OP(PtrEqual, 401)
+_SPIRV_OP(PtrNotEqual, 402)
+_SPIRV_OP(PtrDiff, 403)
 _SPIRV_OP(CopyLogical, 400)
 _SPIRV_OP(GroupNonUniformRotateKHR, 4431)
 _SPIRV_OP(SDotKHR, 4450)

llvm-spirv/test/transcoding/ptr_diff.ll

@@ -0,0 +1,52 @@
+; Check support of OpPtrDiff instruction that was added in SPIR-V 1.4
+
+; RUN: llvm-as %s -o %t.bc
+; RUN: not llvm-spirv --spirv-max-version=1.3 %t.bc 2>&1 | FileCheck --check-prefix=CHECK-ERROR %s
+
+; RUN: llvm-spirv %t.bc -o %t.spv
+; RUN: llvm-spirv %t.spv -to-text -o %t.spt
+; RUN: FileCheck < %t.spt %s --check-prefix=CHECK-SPIRV
+; RUN: spirv-val %t.spv
+
+; RUN: llvm-spirv -r %t.spv -o %t.rev.bc
+; RUN: llvm-dis %t.rev.bc
+; RUN: FileCheck < %t.rev.ll %s --check-prefix=CHECK-LLVM
+
+; CHECK-ERROR: RequiresVersion: Cannot fulfill SPIR-V version restriction:
+; CHECK-ERROR-NEXT: SPIR-V version was restricted to at most 1.3 (66304) but a construct from the input requires SPIR-V version 1.4 (66560) or above
+
+; SPIR-V 1.4
+; CHECK-SPIRV: 66560
+; CHECK-SPIRV: TypeInt [[#TypeInt:]] 32 0
+; CHECK-SPIRV: TypeFloat [[#TypeFloat:]] 32
+; CHECK-SPIRV: TypePointer [[#TypePointer:]] [[#]] [[#TypeFloat]]
+
+; CHECK-SPIRV: Variable [[#TypePointer]] [[#Var:]]
+; CHECK-SPIRV: PtrDiff [[#TypeInt]] [[#]] [[#Var]] [[#Var]]
+
+target datalayout = "e-p:32:32-i64:64-v16:16-v24:32-v32:32-v48:64-v96:128-v192:256-v256:256-v512:512-v1024:1024"
+target triple = "spir64-unknown-unknown"
+
+; Function Attrs: nounwind
+define spir_kernel void @test(float %a) local_unnamed_addr #0 {
+entry:
+  %0 = alloca float, align 4
+  store float %a, ptr %0, align 4
+; CHECK-LLVM: %[[#Arg1:]] = ptrtoint ptr %[[#]] to i64
+; CHECK-LLVM: %[[#Arg2:]] = ptrtoint ptr %[[#]] to i64
+; CHECK-LLVM: %[[#Sub:]] = sub i64 %[[#Arg1]], %[[#Arg2]]
+; CHECK-LLVM: sdiv exact i64 %[[#Sub]], ptrtoint (ptr getelementptr (i32, ptr null, i32 1) to i64)
+  %1 = call spir_func noundef i32 @_Z15__spirv_PtrDiff(ptr %0, ptr %0)
+  ret void
+}
+
+declare spir_func noundef i32 @_Z15__spirv_PtrDiff(ptr, ptr)
+
+attributes #0 = { convergent nounwind writeonly }
+
+!llvm.module.flags = !{!0}
+!opencl.ocl.version = !{!1}
+!opencl.spir.version = !{!1}
+
+!0 = !{i32 1, !"wchar_size", i32 4}
+!1 = !{i32 2, i32 0}

llvm-spirv/test/transcoding/ptr_not_equal.ll

@@ -0,0 +1,60 @@
+; Check support of OpPtrEqual and OpPtrNotEqual instructions that were added in SPIR-V 1.4
+
+; RUN: llvm-as %s -o %t.bc
+; RUN: not llvm-spirv --spirv-max-version=1.3 %t.bc 2>&1 | FileCheck --check-prefix=CHECK-ERROR %s
+
+; RUN: llvm-spirv %t.bc -o %t.spv
+; RUN: llvm-spirv %t.spv -to-text -o %t.spt
+; RUN: FileCheck < %t.spt %s --check-prefix=CHECK-SPIRV
+; RUN: spirv-val %t.spv
+
+; RUN: llvm-spirv -r %t.spv -o %t.rev.bc
+; RUN: llvm-dis %t.rev.bc
+; RUN: FileCheck < %t.rev.ll %s --check-prefix=CHECK-LLVM
+
+; CHECK-ERROR: RequiresVersion: Cannot fulfill SPIR-V version restriction:
+; CHECK-ERROR-NEXT: SPIR-V version was restricted to at most 1.3 (66304) but a construct from the input requires SPIR-V version 1.4 (66560) or above
+
+; SPIR-V 1.4
+; CHECK-SPIRV: 66560
+; CHECK-SPIRV: TypeFloat [[#TypeFloat:]] 32
+; CHECK-SPIRV: TypePointer [[#TypePointer:]] [[#]] [[#TypeFloat]]
+; CHECK-SPIRV: TypeBool [[#TypeBool:]]
+
+; CHECK-SPIRV: Variable [[#TypePointer]] [[#Var1:]]
+; CHECK-SPIRV: Variable [[#TypePointer]] [[#Var2:]]
+; CHECK-SPIRV: PtrEqual [[#TypeBool]] [[#]] [[#Var1]] [[#Var2]]
+; CHECK-SPIRV: PtrNotEqual [[#TypeBool]] [[#]] [[#Var1]] [[#Var2]]
+
+target datalayout = "e-p:32:32-i64:64-v16:16-v24:32-v32:32-v48:64-v96:128-v192:256-v256:256-v512:512-v1024:1024"
+target triple = "spir64-unknown-unknown"
+
+; Function Attrs: nounwind
+define spir_kernel void @test(float %a, float %b) local_unnamed_addr #0 {
+entry:
+  %0 = alloca float, align 4
+  %1 = alloca float, align 4
+  store float %a, ptr %0, align 4
+  store float %b, ptr %1, align 4
+; CHECK-LLVM: %[[#Arg1:]] = ptrtoint ptr %[[#]] to i64
+; CHECK-LLVM: %[[#Arg2:]] = ptrtoint ptr %[[#]] to i64
+; CHECK-LLVM: icmp eq i64 %[[#Arg1]], %[[#Arg2]]
+  %2 = call spir_func noundef i1 @_Z16__spirv_PtrEqual(ptr %0, ptr %1)
+; CHECK-LLVM: %[[#Arg3:]] = ptrtoint ptr %[[#]] to i64
+; CHECK-LLVM: %[[#Arg4:]] = ptrtoint ptr %[[#]] to i64
+; CHECK-LLVM: icmp ne i64 %[[#Arg3]], %[[#Arg4]]
+  %3 = call spir_func noundef i1 @_Z19__spirv_PtrNotEqual(ptr %0, ptr %1)
+  ret void
+}
+
+declare spir_func noundef i1 @_Z16__spirv_PtrEqual(ptr, ptr)
+declare spir_func noundef i1 @_Z19__spirv_PtrNotEqual(ptr, ptr)
+
+attributes #0 = { convergent nounwind writeonly }
+
+!llvm.module.flags = !{!0}
+!opencl.ocl.version = !{!1}
+!opencl.spir.version = !{!1}
+
+!0 = !{i32 1, !"wchar_size", i32 4}
+!1 = !{i32 2, i32 0}