[SYCL] Add macro to disable range rounding for FPGA compilations (#3428)

Set macro SYCL_DISABLE_PARALLEL_FOR_RANGE_ROUNDING for all FPGA compilations
to avoid emitting two versions of the kernel - one by default and another for parallel_for.

Signed-off-by: Soumi Manna [email protected]

Author: smanna12

clang/lib/Frontend/InitPreprocessor.cpp

@@ -1129,6 +1129,12 @@ static void InitializePredefinedMacros(const TargetInfo &TI,
     Builder.defineMacro("__SYCL_DEVICE_ONLY__", "1");
     Builder.defineMacro("SYCL_EXTERNAL", "__attribute__((sycl_device))");
 
+    // Enable __SYCL_DISABLE_PARALLEL_FOR_RANGE_ROUNDING__ macro for
+    // all FPGA compilations.
+    if (TI.getTriple().getSubArch() == llvm::Triple::SPIRSubArch_fpga) {
+      Builder.defineMacro("__SYCL_DISABLE_PARALLEL_FOR_RANGE_ROUNDING__", "1");
+    }
+
     if (TI.getTriple().isNVPTX()) {
         Builder.defineMacro("__SYCL_NVPTX__", "1");
     }

clang/test/Preprocessor/predefined-macros.c

@@ -214,3 +214,16 @@
 // CHECK-HIP-DEV: #define __HIPCC__ 1
 // CHECK-HIP-DEV: #define __HIP_DEVICE_COMPILE__ 1
 // CHECK-HIP-DEV: #define __HIP__ 1
+
+// RUN: %clang_cc1 %s -E -dM -fsycl-is-device \
+// RUN:   -triple spir64_fpga-unknown-unknown-sycldevice -o - \
+// RUN:   | FileCheck -match-full-lines %s --check-prefix=CHECK-RANGE
+// CHECK-RANGE: #define __SYCL_DISABLE_PARALLEL_FOR_RANGE_ROUNDING__ 1
+
+// RUN: %clang_cc1 %s -E -dM -fsycl-is-device -o - \
+// RUN:   | FileCheck -match-full-lines %s --check-prefix=CHECK-NO-RANGE
+
+// RUN: %clang_cc1 %s -E -dM -o - \
+// RUN:   | FileCheck -match-full-lines %s --check-prefix=CHECK-NO-RANGE
+
+// CHECK-NO-RANGE-NOT: #define __SYCL_DISABLE_PARALLEL_FOR_RANGE_ROUNDING__ 1