[Driver][SYCL][FPGA] Implied default device forces emulation (#4801)

When using -Xshardware or -Xssimulation on the command line with
FPGA, the device AOT compilation should be performed by aoc.  This
was not occuring due to the implied default device when one such
object or archive was supplied on the command line.
Make adjustments to our discovery of FPGA hardware/simulation mode
by only checking the actual FPGA toolchain and not just the first
offload toolchain encountered.

Author: mdtoguchi

clang/lib/Driver/Driver.cpp

@@ -1473,17 +1473,22 @@ Compilation *Driver::BuildCompilation(ArrayRef<const char *> ArgList) {
   // Determine FPGA emulation status.
   if (C->hasOffloadToolChain<Action::OFK_SYCL>()) {
     auto SYCLTCRange = C->getOffloadToolChains<Action::OFK_SYCL>();
-    ArgStringList TargetArgs;
-    const ToolChain *TC = SYCLTCRange.first->second;
-    const toolchains::SYCLToolChain *SYCLTC =
-        static_cast<const toolchains::SYCLToolChain *>(TC);
-    SYCLTC->TranslateBackendTargetArgs(SYCLTC->getTriple(), *TranslatedArgs,
-                                       TargetArgs);
-    for (StringRef ArgString : TargetArgs) {
-      if (ArgString.equals("-hardware") || ArgString.equals("-simulation")) {
-        setFPGAEmulationMode(false);
-        break;
+    for (auto TI = SYCLTCRange.first, TE = SYCLTCRange.second; TI != TE; ++TI) {
+      if (TI->second->getTriple().getSubArch() !=
+          llvm::Triple::SPIRSubArch_fpga)
+        continue;
+      ArgStringList TargetArgs;
+      const toolchains::SYCLToolChain *FPGATC =
+          static_cast<const toolchains::SYCLToolChain *>(TI->second);
+      FPGATC->TranslateBackendTargetArgs(FPGATC->getTriple(), *TranslatedArgs,
+                                         TargetArgs);
+      for (StringRef ArgString : TargetArgs) {
+        if (ArgString.equals("-hardware") || ArgString.equals("-simulation")) {
+          setFPGAEmulationMode(false);
+          break;
+        }
       }
+      break;
     }
   }
 

clang/test/Driver/sycl-offload-intelfpga.cpp

@@ -504,3 +504,10 @@
 // RUN:   | FileCheck -check-prefix=ERROR_BUNDLE_CHECK %s
 // ERROR_BUNDLE_CHECK-NOT: clang-offload-bundler{{.*}} "-targets=sycl-fpga_aoc{{(x|r|r_emu|o)}}-intel-unknown"{{.*}} "-check-section"
 // ERROR_BUNDLE_CHECK-NOT: error: file too small to be an archive
+
+/// Implied default device should not prevent hardware/simulation
+// RUN:  %clangxx -### -target x86_64-unknown-linux-gnu -fsycl -fintelfpga -Xshardware %S/Inputs/SYCL/liblin64.a %s 2>&1 \
+// RUN:    | FileCheck -check-prefix IMPLIED_DEVICE_HARDWARE -DBEOPT=hardware %s
+// RUN:  %clangxx -### -target x86_64-unknown-linux-gnu -fsycl -fintelfpga -Xssimulation %S/Inputs/SYCL/liblin64.a %s 2>&1 \
+// RUN:    | FileCheck -check-prefix IMPLIED_DEVICE_HARDWARE -DBEOPT=simulation %s
+// IMPLIED_DEVICE_HARDWARE: aoc{{.*}} "-[[BEOPT]]"