[AMDGPU][HIP] Improve opt-level handling

Summary:
The HIP toolchain invokes `llc` without an explicit opt-level, meaning
it always uses the default (-O2). This makes it impossible to use -O1,
for example. The HIP toolchain also coerces -Os/-Oz to -O2 even when
invoking opt, and it coerces -Og to -O2 rather than -O1.

Forward the opt-level to `llc` as well as `opt`, and only coerce levels
where it is required.

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D70987

clang/lib/Driver/ToolChains/HIP.cpp

@@ -62,6 +62,34 @@ static const char *getOutputFileName(Compilation &C, StringRef Base,
   }
   return OutputFileName;
 }
+
+static void addOptLevelArgs(const llvm::opt::ArgList &Args,
+                            llvm::opt::ArgStringList &CmdArgs,
+                            bool IsLlc = false) {
+  if (Arg *A = Args.getLastArg(options::OPT_O_Group)) {
+    StringRef OOpt = "3";
+    if (A->getOption().matches(options::OPT_O4) ||
+        A->getOption().matches(options::OPT_Ofast))
+      OOpt = "3";
+    else if (A->getOption().matches(options::OPT_O0))
+      OOpt = "0";
+    else if (A->getOption().matches(options::OPT_O)) {
+      // Clang and opt support -Os/-Oz; llc only supports -O0, -O1, -O2 and -O3
+      // so we map -Os/-Oz to -O2.
+      // Only clang supports -Og, and maps it to -O1.
+      // We map anything else to -O2.
+      OOpt = llvm::StringSwitch<const char *>(A->getValue())
+                 .Case("1", "1")
+                 .Case("2", "2")
+                 .Case("3", "3")
+                 .Case("s", IsLlc ? "2" : "s")
+                 .Case("z", IsLlc ? "2" : "z")
+                 .Case("g", "1")
+                 .Default("2");
+    }
+    CmdArgs.push_back(Args.MakeArgString("-O" + OOpt));
+  }
+}
 } // namespace
 
 const char *AMDGCN::Linker::constructLLVMLinkCommand(
@@ -93,25 +121,7 @@ const char *AMDGCN::Linker::constructOptCommand(
   // The input to opt is the output from llvm-link.
   OptArgs.push_back(InputFileName);
   // Pass optimization arg to opt.
-  if (Arg *A = Args.getLastArg(options::OPT_O_Group)) {
-    StringRef OOpt = "3";
-    if (A->getOption().matches(options::OPT_O4) ||
-        A->getOption().matches(options::OPT_Ofast))
-      OOpt = "3";
-    else if (A->getOption().matches(options::OPT_O0))
-      OOpt = "0";
-    else if (A->getOption().matches(options::OPT_O)) {
-      // -Os, -Oz, and -O(anything else) map to -O2
-      OOpt = llvm::StringSwitch<const char *>(A->getValue())
-                 .Case("1", "1")
-                 .Case("2", "2")
-                 .Case("3", "3")
-                 .Case("s", "2")
-                 .Case("z", "2")
-                 .Default("2");
-    }
-    OptArgs.push_back(Args.MakeArgString("-O" + OOpt));
-  }
+  addOptLevelArgs(Args, OptArgs);
   OptArgs.push_back("-mtriple=amdgcn-amd-amdhsa");
   OptArgs.push_back(Args.MakeArgString("-mcpu=" + SubArchName));
 
@@ -136,10 +146,15 @@ const char *AMDGCN::Linker::constructLlcCommand(
     llvm::StringRef OutputFilePrefix, const char *InputFileName,
     bool OutputIsAsm) const {
   // Construct llc command.
-  ArgStringList LlcArgs{
-      InputFileName, "-mtriple=amdgcn-amd-amdhsa",
-      Args.MakeArgString(Twine("-filetype=") + (OutputIsAsm ? "asm" : "obj")),
-      Args.MakeArgString("-mcpu=" + SubArchName)};
+  ArgStringList LlcArgs;
+  // The input to llc is the output from opt.
+  LlcArgs.push_back(InputFileName);
+  // Pass optimization arg to llc.
+  addOptLevelArgs(Args, LlcArgs, /*IsLlc=*/true);
+  LlcArgs.push_back("-mtriple=amdgcn-amd-amdhsa");
+  LlcArgs.push_back(Args.MakeArgString("-mcpu=" + SubArchName));
+  LlcArgs.push_back(
+      Args.MakeArgString(Twine("-filetype=") + (OutputIsAsm ? "asm" : "obj")));
 
   // Extract all the -m options
   std::vector<llvm::StringRef> Features;

clang/test/Driver/hip-toolchain-mllvm.hip

@@ -18,8 +18,9 @@
 // CHECK-SAME: "-o" [[OPT_803_BC:".*-gfx803-optimized.*bc"]]
 
 // CHECK: [[LLC: ".*llc"]] [[OPT_803_BC]]
-// CHECK-SAME: "-mtriple=amdgcn-amd-amdhsa" "-filetype=obj"
+// CHECK-SAME: "-mtriple=amdgcn-amd-amdhsa"
 // CHECK-SAME: {{.*}} "-mcpu=gfx803"
+// CHECK-SAME: "-filetype=obj"
 // CHECK-SAME: "-amdgpu-function-calls=0" "-o" {{".*-gfx803-.*o"}}
 
 // CHECK: [[CLANG]] "-cc1" "-triple" "amdgcn-amd-amdhsa"
@@ -33,6 +34,7 @@
 // CHECK-SAME: "-o" [[OPT_900_BC:".*-gfx900-optimized.*bc"]]
 
 // CHECK: [[LLC]] [[OPT_900_BC]]
-// CHECK-SAME: "-mtriple=amdgcn-amd-amdhsa" "-filetype=obj"
+// CHECK-SAME: "-mtriple=amdgcn-amd-amdhsa"
 // CHECK-SAME: {{.*}} "-mcpu=gfx900"
+// CHECk-SAME: "-filetype=obj"
 // CHECK-SAME: "-amdgpu-function-calls=0" "-o" {{".*-gfx900-.*o"}}

clang/test/Driver/hip-toolchain-no-rdc.hip

@@ -34,8 +34,9 @@
 // CHECK-SAME: "-o" [[OPT_BC_DEV_A_803:".*-gfx803-optimized.*bc"]]
 
 // CHECK: [[LLC: ".*llc"]] [[OPT_BC_DEV_A_803]] "-mtriple=amdgcn-amd-amdhsa"
+// CHECK-SAME: "-mcpu=gfx803"
 // CHECK-SAME: "-filetype=obj"
-// CHECK-SAME: "-mcpu=gfx803" "-o" [[OBJ_DEV_A_803:".*-gfx803-.*o"]]
+// CHECK-SAME: "-o" [[OBJ_DEV_A_803:".*-gfx803-.*o"]]
 
 // CHECK: [[LLD: ".*lld"]] "-flavor" "gnu" "-shared"
 // CHECK-SAME: "-o" "[[IMG_DEV_A_803:.*out]]" [[OBJ_DEV_A_803]]
@@ -62,8 +63,9 @@
 // CHECK-SAME: "-o" [[OPT_BC_DEV_A_900:".*-gfx900-optimized.*bc"]]
 
 // CHECK: [[LLC: ".*llc"]] [[OPT_BC_DEV_A_900]] "-mtriple=amdgcn-amd-amdhsa"
+// CHECK-SAME: "-mcpu=gfx900"
 // CHECK-SAME: "-filetype=obj"
-// CHECK-SAME: "-mcpu=gfx900" "-o" [[OBJ_DEV_A_900:".*-gfx900-.*o"]]
+// CHECK-SAME: "-o" [[OBJ_DEV_A_900:".*-gfx900-.*o"]]
 
 // CHECK: [[LLD: ".*lld"]] "-flavor" "gnu" "-shared"
 // CHECK-SAME: "-o" "[[IMG_DEV_A_900:.*out]]" [[OBJ_DEV_A_900]]
@@ -106,8 +108,9 @@
 // CHECK-SAME: "-o" [[OPT_BC_DEV_B_803:".*-gfx803-optimized.*bc"]]
 
 // CHECK: [[LLC: ".*llc"]] [[OPT_BC_DEV_B_803]] "-mtriple=amdgcn-amd-amdhsa"
+// CHECK-SAME: "-mcpu=gfx803"
 // CHECK-SAME: "-filetype=obj"
-// CHECK-SAME: "-mcpu=gfx803" "-o" [[OBJ_DEV_B_803:".*-gfx803-.*o"]]
+// CHECK-SAME: "-o" [[OBJ_DEV_B_803:".*-gfx803-.*o"]]
 
 // CHECK: [[LLD: ".*lld"]] "-flavor" "gnu" "-shared"
 // CHECK-SAME: "-o" "[[IMG_DEV_B_803:.*out]]" [[OBJ_DEV_B_803]]
@@ -134,8 +137,9 @@
 // CHECK-SAME: "-o" [[OPT_BC_DEV_B_900:".*-gfx900-optimized.*bc"]]
 
 // CHECK: [[LLC: ".*llc"]] [[OPT_BC_DEV_B_900]] "-mtriple=amdgcn-amd-amdhsa"
+// CHECk-SAME: "-mcpu=gfx900"
 // CHECK-SAME: "-filetype=obj"
-// CHECK-SAME: "-mcpu=gfx900" "-o" [[OBJ_DEV_B_900:".*-gfx900-.*o"]]
+// CHECK-SAME: "-o" [[OBJ_DEV_B_900:".*-gfx900-.*o"]]
 
 // CHECK: [[LLD: ".*lld"]] "-flavor" "gnu" "-shared"
 // CHECK-SAME: "-o" "[[IMG_DEV_B_900:.*out]]" [[OBJ_DEV_B_900]]

clang/test/Driver/hip-toolchain-opt.hip

@@ -0,0 +1,101 @@
+// REQUIRES: clang-driver
+// REQUIRES: x86-registered-target
+// REQUIRES: amdgpu-registered-target
+
+// RUN: %clang -### \
+// RUN:   -target x86_64-unknown-linux-gnu \
+// RUN:   -x hip --cuda-gpu-arch=gfx900 \
+// RUN:   -c -nogpulib \
+// RUN:   %S/Inputs/hip_multiple_inputs/b.hip \
+// RUN: 2>&1 | FileCheck --check-prefixes=ALL,DEFAULT %s
+
+// RUN: %clang -### -O0 \
+// RUN:   -target x86_64-unknown-linux-gnu \
+// RUN:   -x hip --cuda-gpu-arch=gfx900 \
+// RUN:   -c -nogpulib \
+// RUN:   %S/Inputs/hip_multiple_inputs/b.hip \
+// RUN: 2>&1 | FileCheck --check-prefixes=ALL,O0 %s
+
+// RUN: %clang -### -O1 \
+// RUN:   -target x86_64-unknown-linux-gnu \
+// RUN:   -x hip --cuda-gpu-arch=gfx900 \
+// RUN:   -c -nogpulib \
+// RUN:   %S/Inputs/hip_multiple_inputs/b.hip \
+// RUN: 2>&1 | FileCheck --check-prefixes=ALL,O1 %s
+
+// RUN: %clang -### -O2 \
+// RUN:   -target x86_64-unknown-linux-gnu \
+// RUN:   -x hip --cuda-gpu-arch=gfx900 \
+// RUN:   -c -nogpulib \
+// RUN:   %S/Inputs/hip_multiple_inputs/b.hip \
+// RUN: 2>&1 | FileCheck --check-prefixes=ALL,O2 %s
+
+// RUN: %clang -### -O3 \
+// RUN:   -target x86_64-unknown-linux-gnu \
+// RUN:   -x hip --cuda-gpu-arch=gfx900 \
+// RUN:   -c -nogpulib \
+// RUN:   %S/Inputs/hip_multiple_inputs/b.hip \
+// RUN: 2>&1 | FileCheck --check-prefixes=ALL,O3 %s
+
+// RUN: %clang -### -Os \
+// RUN:   -target x86_64-unknown-linux-gnu \
+// RUN:   -x hip --cuda-gpu-arch=gfx900 \
+// RUN:   -c -nogpulib \
+// RUN:   %S/Inputs/hip_multiple_inputs/b.hip \
+// RUN: 2>&1 | FileCheck --check-prefixes=ALL,Os %s
+
+// RUN: %clang -### -Oz \
+// RUN:   -target x86_64-unknown-linux-gnu \
+// RUN:   -x hip --cuda-gpu-arch=gfx900 \
+// RUN:   -c -nogpulib \
+// RUN:   %S/Inputs/hip_multiple_inputs/b.hip \
+// RUN: 2>&1 | FileCheck --check-prefixes=ALL,Oz %s
+
+// RUN: %clang -### -Og \
+// RUN:   -target x86_64-unknown-linux-gnu \
+// RUN:   -x hip --cuda-gpu-arch=gfx900 \
+// RUN:   -c -nogpulib \
+// RUN:   %S/Inputs/hip_multiple_inputs/b.hip \
+// RUN: 2>&1 | FileCheck --check-prefixes=ALL,Og %s
+
+// ALL: "{{.*}}clang{{.*}}" "-cc1" "-triple" "amdgcn-amd-amdhsa"
+// DEFAULT-NOT: "-O{{.}}"
+// O0-SAME: "-O0"
+// O1-SAME: "-O1"
+// O2-SAME: "-O2"
+// O3-SAME: "-O3"
+// Os-SAME: "-Os"
+// Oz-SAME: "-Oz"
+// Og-SAME: "-Og"
+
+// ALL: "{{.*}}opt"
+// DEFAULT-NOT: "-O{{.}}"
+// O0-SAME: "-O0"
+// O1-SAME: "-O1"
+// O2-SAME: "-O2"
+// O3-SAME: "-O3"
+// Os-SAME: "-Os"
+// Oz-SAME: "-Oz"
+// Og-SAME: "-O1"
+// ALL-SAME: "-mtriple=amdgcn-amd-amdhsa"
+
+// ALL: "{{.*}}llc"
+// DEFAULT-NOT: "-O{{.}}"
+// O0-SAME: "-O0"
+// O1-SAME: "-O1"
+// O2-SAME: "-O2"
+// O3-SAME: "-O3"
+// Os-SAME: "-O2"
+// Oz-SAME: "-O2"
+// Og-SAME: "-O1"
+// ALL-SAME: "-mtriple=amdgcn-amd-amdhsa"
+
+// ALL: "{{.*}}clang{{.*}}" "-cc1" "-triple" "x86_64-unknown-linux-gnu"
+// DEFAULT-NOT: "-O{{.}}"
+// O0-SAME: "-O0"
+// O1-SAME: "-O1"
+// O2-SAME: "-O2"
+// O3-SAME: "-O3"
+// Os-SAME: "-Os"
+// Oz-SAME: "-Oz"
+// Og-SAME: "-Og"

clang/test/Driver/hip-toolchain-rdc.hip

@@ -40,13 +40,14 @@
 // CHECK-SAME: "-o" [[OPT_BC_DEV1:".*-gfx803-optimized.*bc"]]
 
 // CHECK: [[LLC: ".*llc"]] [[OPT_BC_DEV1]] "-mtriple=amdgcn-amd-amdhsa"
+// CHECK-SAME: "-mcpu=gfx803"
 // CHECK-SAME: "-filetype=obj"
-// CHECK-SAME: "-mcpu=gfx803" "-o" [[OBJ_DEV1:".*-gfx803-.*o"]]
+// CHECK-SAME: "-o" [[OBJ_DEV1:".*-gfx803-.*o"]]
 
 // CHECK: [[LLD: ".*lld"]] "-flavor" "gnu" "-shared"
 // CHECK-SAME: "-o" "[[IMG_DEV1:.*out]]" [[OBJ_DEV1]]
 
-// CHECK: [[CLANG]] "-cc1" "-triple" "amdgcn-amd-amdhsa" 
+// CHECK: [[CLANG]] "-cc1" "-triple" "amdgcn-amd-amdhsa"
 // CHECK-SAME: "-aux-triple" "x86_64-unknown-linux-gnu"
 // CHECK-SAME: "-emit-llvm-bc"
 // CHECK-SAME: {{.*}} "-main-file-name" "a.cu" {{.*}} "-target-cpu" "gfx900"
@@ -72,8 +73,9 @@
 // CHECK-SAME: "-o" [[OPT_BC_DEV2:".*-gfx900-optimized.*bc"]]
 
 // CHECK: [[LLC]] [[OPT_BC_DEV2]] "-mtriple=amdgcn-amd-amdhsa"
+// CHECk-SAME: "-mcpu=gfx900"
 // CHECK-SAME: "-filetype=obj"
-// CHECK-SAME: "-mcpu=gfx900" "-o" [[OBJ_DEV2:".*-gfx900-.*o"]]
+// CHECK-SAME: "-o" [[OBJ_DEV2:".*-gfx900-.*o"]]
 
 // CHECK: [[LLD]] "-flavor" "gnu" "-shared"
 // CHECK-SAME: "-o" "[[IMG_DEV2:.*out]]" [[OBJ_DEV2]]