Handle SPIR AOT

Author: victor-eds

llvm/test/tools/sycl-post-link/spec-constants/SYCL-alloca-error.ll

@@ -0,0 +1,24 @@
+; RUN: sycl-post-link -spec-const=emulation %s 2>&1 | FileCheck %s
+
+; This test checks the `-spec-const` pass on SPIR-V targets and emulation mode,
+; i.e., on AOT SPIR-V targets. In this scenario, 'llvm.sycl.alloca' intrinsics
+; must be left unmodified.
+
+; Note that coming from clang this case should never be reached.
+
+; CHECK: sycl-post-link NOTE: no modifications to the input LLVM IR have been made
+
+target triple = "spir64_x86_64"
+
+%"class.sycl::_V1::specialization_id" = type { i64 }
+
+@size_i64 = addrspace(1) constant %"class.sycl::_V1::specialization_id" { i64 10 }, align 8
+
+@size_i64_stable_name = private unnamed_addr constant [36 x i8] c"_ZTS14name_generatorIL_Z8size_i64EE\00", align 1
+
+define dso_local void @private_alloca() {
+  call ptr @llvm.sycl.alloca.p0.p4.p4.p4.f64(ptr addrspace(4) addrspacecast (ptr @size_i64_stable_name to ptr addrspace(4)), ptr addrspace(4) addrspacecast (ptr addrspace(1) @size_i64 to ptr addrspace(4)), ptr addrspace(4) null, double 0.000000e+00, i64 8)
+  ret void
+}
+
+declare ptr @llvm.sycl.alloca.p0.p4.p4.p4.f32(ptr addrspace(4), ptr addrspace(4), ptr addrspace(4), float, i64)

llvm/tools/sycl-post-link/SpecConstants.cpp

@@ -20,6 +20,7 @@
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/IntrinsicInst.h"
 #include "llvm/IR/Operator.h"
+#include "llvm/TargetParser/Triple.h"
 
 #include <vector>
 
@@ -815,12 +816,18 @@ PreservedAnalyses SpecConstantsPass::run(Module &M,
   // intrinsic to find its calls and lower them depending on the HandlingMode.
   bool IRModified = false;
   LLVMContext &Ctx = M.getContext();
+  bool IsSPIREmulated =
+      Triple(M.getTargetTriple()).isSPIR() && Mode == HandlingMode::emulation;
   for (Function &F : M) {
     if (!F.isDeclaration())
       continue;
 
     const bool IsSYCLAlloca = F.getIntrinsicID() == Intrinsic::sycl_alloca;
 
+    // 'llvm.sycl.alloca' is not supported in emulation mode on SPIR-V targets.
+    if (IsSPIREmulated && IsSYCLAlloca)
+      continue;
+
     if (!F.getName().starts_with(SYCL_GET_SCALAR_2020_SPEC_CONST_VAL) &&
         !F.getName().starts_with(SYCL_GET_COMPOSITE_2020_SPEC_CONST_VAL) &&
         !IsSYCLAlloca)