[SYCL] Set -O0 as the default SYCL device optimization if -g is passed (

intel#16408) Set `O0` as the default SYCL device optimization if `-g` is passed and optimization level is not provided explicitly. Use of `'-g'` without any optimization-level option will turn off compiler optimizations similar to use of `'-O0'`.
reble · Dec 19, 2024 · 9a8613a · 9a8613a
1 parent fe98db3
commit 9a8613a
Show file tree

Hide file tree

Showing 5 changed files with 100 additions and 8 deletions.
diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -5665,9 +5665,27 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
         CmdArgs.push_back("-Wno-sycl-strict");
       }
 
-      // Set O2 optimization level by default
-      if (!Args.getLastArg(options::OPT_O_Group))
-        CmdArgs.push_back("-O2");
+      // If no optimization controlling flags (-O) are provided, check if
+      // any debug information flags(-g) are passed.
+      // "-fintelfpga" implies "-g" and we preserve the default optimization for
+      // this flow(-O2).
+      // if "-g" is explicitly passed from the command-line, set default
+      // optimization to -O0.
+
+      if (!Args.hasArgNoClaim(options::OPT_O_Group, options::OPT__SLASH_O)) {
+        StringRef OptLevel = "-O2";
+        const Arg *DebugInfoGroup = Args.getLastArg(options::OPT_g_Group);
+        // -fintelfpga -g case
+        if ((Args.hasArg(options::OPT_fintelfpga) &&
+             Args.hasMultipleArgs(options::OPT_g_Group)) ||
+            /* -fsycl -g case */ (!Args.hasArg(options::OPT_fintelfpga) &&
+                                  DebugInfoGroup)) {
+          if (!DebugInfoGroup->getOption().matches(options::OPT_g0)) {
+            OptLevel = "-O0";
+          }
+        }
+        CmdArgs.push_back(OptLevel.data());
+      }
 
       // Add the integration header option to generate the header.
       StringRef Header(D.getIntegrationHeader(Input.getBaseInput()));
@@ -10931,7 +10949,25 @@ static std::string getSYCLPostLinkOptimizationLevel(const ArgList &Args) {
                     [=](char c) { return c == S[0]; }))
       return std::string("-O") + S[0];
   }
-
+  // If no optimization controlling flags (-O) are provided, check if
+  // any debug information flags(-g) are passed.
+  // "-fintelfpga" implies "-g" and we preserve the default optimization for
+  // this flow(-O2).
+  // if "-g" is explicitly passed from the command-line, set default
+  // optimization to -O0.
+
+  if (!Args.hasArg(options::OPT_O_Group)) {
+    const Arg *DebugInfoGroup = Args.getLastArg(options::OPT_g_Group);
+    // -fintelfpga -g case
+    if ((Args.hasArg(options::OPT_fintelfpga) &&
+         Args.hasMultipleArgs(options::OPT_g_Group)) ||
+        /* -fsycl -g case */
+        (!Args.hasArg(options::OPT_fintelfpga) && DebugInfoGroup)) {
+      if (!DebugInfoGroup->getOption().matches(options::OPT_g0)) {
+        return "-O0";
+      }
+    }
+  }
   // The default for SYCL device code optimization
   return "-O2";
 }

diff --git a/clang/test/Driver/sycl-device-optimizations.cpp b/clang/test/Driver/sycl-device-optimizations.cpp
@@ -53,3 +53,59 @@
 // RUN:   %clang -### -fsycl --offload-new-driver %s 2>&1 \
 // RUN:   | FileCheck -check-prefix=CHECK-NO-THRESH %s
 // CHECK-NO-THRESH-NOT: "-mllvm" "-inline-threshold
+
+/// Check that optimizations for sycl device are disabled with -g passed:
+// RUN:   %clang -### -fsycl -g %s 2>&1 \
+// RUN:   | FileCheck -check-prefix=CHECK-DEBUG %s
+// RUN:   %clang_cl -### -fsycl -g %s 2>&1 \
+// RUN:   | FileCheck -check-prefix=CHECK-DEBUG %s
+// CHECK-DEBUG: clang{{.*}} "-fsycl-is-device{{.*}}" "-O0"
+// CHECK-DEBUG: sycl-post-link{{.*}} "-O0"
+// CHECK-DEBUG-NOT: "-O2"
+
+/// Check that optimizations for sycl device are enabled with -g and O2 passed:
+// RUN:   %clang -### -fsycl -O2 -g %s 2>&1 \
+// RUN:   | FileCheck -check-prefix=CHECK-G-O2 %s
+// For clang_cl, -O2 maps to -O3
+// RUN:   %clang_cl -### -fsycl -O2 -g %s 2>&1 \
+// RUN:   | FileCheck -check-prefix=CHECK-G-O3 %s
+// CHECK-G-O2: clang{{.*}} "-fsycl-is-device{{.*}}" "-O2"
+// CHECK-G-O2: sycl-post-link{{.*}} "-O2"
+// CHECK-G-O2-NOT: "-O0"
+// CHECK-G-O3: clang{{.*}} "-fsycl-is-device{{.*}}" "-O3"
+// CHECK-G-O3: sycl-post-link{{.*}} "-O3"
+// CHECK-G-O3-NOT: "-O0"
+
+/// Check that -O2 is passed for FPGA
+// RUN:   %clang -### -fintelfpga -fsycl-early-optimizations %s 2>&1 \
+// RUN:   | FileCheck -check-prefix=CHECK-FPGA %s
+// RUN:   %clang_cl -### -fintelfpga -fsycl-early-optimizations %s 2>&1 \
+// RUN:   | FileCheck -check-prefix=CHECK-FPGA %s
+// CHECK-FPGA: clang{{.*}} "-fsycl-is-device{{.*}}" "-O2"
+// CHECK-FPGA: sycl-post-link{{.*}} "-O2"
+// CHECK-FPGA-NOT: "-O0"
+
+/// Check that -O2 preserves for FPGA when it's explicitly passed
+// RUN:   %clang -### -O2 -fintelfpga -fsycl-early-optimizations %s 2>&1 \
+// RUN:   | FileCheck -check-prefix=CHECK-FPGA-O2 %s
+// For clang_cl, -O2 maps to -O3
+// RUN:   %clang_cl -### -O2 -fintelfpga -fsycl-early-optimizations %s 2>&1 \
+// RUN:   | FileCheck -check-prefix=CHECK-FPGA-O3 %s
+// CHECK-FPGA-O2: clang{{.*}} "-fsycl-is-device{{.*}}" "-O2"
+// CHECK-FPGA-O2: sycl-post-link{{.*}} "-O2"
+// CHECK-FPGA-O2-NOT: "-O0"
+// CHECK-FPGA-O3: clang{{.*}} "-fsycl-is-device{{.*}}" "-O3"
+// CHECK-FPGA-O3: sycl-post-link{{.*}} "-O3"
+// CHECK-FPGA-O3-NOT: "-O0"
+
+/// Check that -O0 is passed for FPGA when -g is explicitly passed
+// RUN:   %clang -### -fintelfpga -g %s 2>&1 \
+// RUN:   | FileCheck -check-prefix=CHECK-FPGA-O0 %s
+// RUN:   %clang_cl -### -fintelfpga -g %s 2>&1 \
+// RUN:   | FileCheck -check-prefix=CHECK-FPGA-O0 %s
+// CHECK-FPGA-O0: clang{{.*}} "-fsycl-is-device{{.*}}" "-O0"
+// CHECK-FPGA-O0: sycl-post-link{{.*}} "-O0"
+// CHECK-FPGA-O0-NOT: "-O2"
+
+
+
diff --git a/clang/test/Driver/sycl-offload-intelfpga.cpp b/clang/test/Driver/sycl-offload-intelfpga.cpp
@@ -228,8 +228,8 @@
 // RUN:   | FileCheck -check-prefix=CHK-TOOLS-IMPLIED-OPTS %s
 // RUN:   %clang_cl -### -fintelfpga -Zi -Od -Xs "-DFOO1 -DFOO2" -Xshardware %s 2>&1 \
 // RUN:   | FileCheck -check-prefix=CHK-TOOLS-IMPLIED-OPTS %s
-// CHK-TOOLS-IMPLIED-OPTS-NOT: clang{{.*}} "-fsycl-is-device"{{.*}} "-O0"
-// CHK-TOOLS-IMPLIED-OPTS: sycl-post-link{{.*}} "-O2"
+// CHK-TOOLS-IMPLIED-OPTS: clang{{.*}} "-fsycl-is-device"{{.*}} "-fno-sycl-early-optimizations"{{.*}} "-O0"
+// CHK-TOOLS-IMPLIED-OPTS: sycl-post-link{{.*}} "-O0"
 // CHK-TOOLS-IMPLIED-OPTS: aoc{{.*}} "-g" "-DFOO1" "-DFOO2"
 
 /// shared objects should not be checked for FPGA contents

diff --git a/sycl/test-e2e/InvokeSimd/Regression/ImplicitSubgroup/debug_symbols.cpp b/sycl/test-e2e/InvokeSimd/Regression/ImplicitSubgroup/debug_symbols.cpp
@@ -1,5 +1,5 @@
 // Check that full compilation works:
-// RUN: %clangxx -DIMPL_SUBGROUP -fsycl -fno-sycl-device-code-split-esimd -Xclang -fsycl-allow-func-ptr -g %S/../debug_symbols.cpp -o %t.out
+// RUN: %clangxx -DIMPL_SUBGROUP -fsycl -fno-sycl-device-code-split-esimd -Xclang -fsycl-allow-func-ptr -g -O2 %S/../debug_symbols.cpp -o %t.out
 // RUN: env IGC_VCSaveStackCallLinkage=1 IGC_VCDirectCallsOnly=1 %{run} %t.out
 //
 // VISALTO enable run

diff --git a/sycl/test-e2e/InvokeSimd/Regression/debug_symbols.cpp b/sycl/test-e2e/InvokeSimd/Regression/debug_symbols.cpp
@@ -1,5 +1,5 @@
 // Check that full compilation works:
-// RUN: %{build} -fno-sycl-device-code-split-esimd -Xclang -fsycl-allow-func-ptr -g -o %t.out
+// RUN: %{build} -fno-sycl-device-code-split-esimd -Xclang -fsycl-allow-func-ptr -g -O2 -o %t.out
 // RUN: env IGC_VCSaveStackCallLinkage=1 IGC_VCDirectCallsOnly=1 %{run} %t.out
 //
 // VISALTO enable run