[clang] 02ef996 - [RISCV] Prevent __builtin_riscv_orc_b_64 from being compiled RV32 target.

[Craig Topper via cfe-commits]

Author: Craig Topper
Date: 2021-04-08T11:34:56-07:00
New Revision: 02ef9963e1ad1e6ded539c830861a074b879dc70

URL: https://github.com/llvm/llvm-project/commit/02ef9963e1ad1e6ded539c830861a074b879dc70
DIFF: https://github.com/llvm/llvm-project/commit/02ef9963e1ad1e6ded539c830861a074b879dc70.diff

LOG: [RISCV] Prevent __builtin_riscv_orc_b_64 from being compiled RV32 target.

The backend can't handle this and will throw a fatal error from
type legalization. It's easy enough to fix that for this intrinsic
by just splitting the IR intrinsic since it works on individual bytes.

There will be other intrinsics in the future that would be harder
to support through splitting, for example grev, gorc, and shfl. Those
would require a compare and a select be inserted to check the MSB of
their control input.

This patch adds support for preventing this in the frontend with
a nice diagnostic.

Reviewed By: frasercrmck

Differential Revision: https://reviews.llvm.org/D99984

Added: 
    clang/test/CodeGen/RISCV/rvb-intrinsics/riscv32-zbb-error.c

Modified: 
    clang/include/clang/Basic/BuiltinsRISCV.def
    clang/lib/Basic/Targets/RISCV.cpp
    clang/lib/Basic/Targets/RISCV.h
    clang/lib/Sema/SemaChecking.cpp

Removed: 
    


################################################################################
diff  --git a/clang/include/clang/Basic/BuiltinsRISCV.def b/clang/include/clang/Basic/BuiltinsRISCV.def
index e0b28011e61ad..8105263ca3ca6 100644
--- a/clang/include/clang/Basic/BuiltinsRISCV.def
+++ b/clang/include/clang/Basic/BuiltinsRISCV.def
@@ -19,7 +19,7 @@
 
 // Zbb extension
 TARGET_BUILTIN(__builtin_riscv_orc_b_32, "ZiZi", "nc", "experimental-zbb")
-TARGET_BUILTIN(__builtin_riscv_orc_b_64, "WiWi", "nc", "experimental-zbb")
+TARGET_BUILTIN(__builtin_riscv_orc_b_64, "WiWi", "nc", "experimental-zbb,64bit")
 
 // Zbc extension
 TARGET_BUILTIN(__builtin_riscv_clmul, "LiLiLi", "nc", "experimental-zbc")

diff  --git a/clang/lib/Basic/Targets/RISCV.cpp b/clang/lib/Basic/Targets/RISCV.cpp
index 4ca41414a9d62..1f31f471db3a4 100644
--- a/clang/lib/Basic/Targets/RISCV.cpp
+++ b/clang/lib/Basic/Targets/RISCV.cpp
@@ -239,6 +239,16 @@ ArrayRef<Builtin::Info> RISCVTargetInfo::getTargetBuiltins() const {
                                              Builtin::FirstTSBuiltin);
 }
 
+bool RISCVTargetInfo::initFeatureMap(
+    llvm::StringMap<bool> &Features, DiagnosticsEngine &Diags, StringRef CPU,
+    const std::vector<std::string> &FeaturesVec) const {
+
+  if (getTriple().getArch() == llvm::Triple::riscv64)
+    Features["64bit"] = true;
+
+  return TargetInfo::initFeatureMap(Features, Diags, CPU, FeaturesVec);
+}
+
 /// Return true if has this feature, need to sync with handleTargetFeatures.
 bool RISCVTargetInfo::hasFeature(StringRef Feature) const {
   bool Is64Bit = getTriple().getArch() == llvm::Triple::riscv64;
@@ -246,6 +256,7 @@ bool RISCVTargetInfo::hasFeature(StringRef Feature) const {
       .Case("riscv", true)
       .Case("riscv32", !Is64Bit)
       .Case("riscv64", Is64Bit)
+      .Case("64bit", Is64Bit)
       .Case("m", HasM)
       .Case("a", HasA)
       .Case("f", HasF)

diff  --git a/clang/lib/Basic/Targets/RISCV.h b/clang/lib/Basic/Targets/RISCV.h
index 4fc8cd1e22dfb..4e650d3b2dc16 100644
--- a/clang/lib/Basic/Targets/RISCV.h
+++ b/clang/lib/Basic/Targets/RISCV.h
@@ -99,6 +99,11 @@ class RISCVTargetInfo : public TargetInfo {
 
   std::string convertConstraint(const char *&Constraint) const override;
 
+  bool
+  initFeatureMap(llvm::StringMap<bool> &Features, DiagnosticsEngine &Diags,
+                 StringRef CPU,
+                 const std::vector<std::string> &FeaturesVec) const override;
+
   bool hasFeature(StringRef Feature) const override;
 
   bool handleTargetFeatures(std::vector<std::string> &Features,

diff  --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index 1d39de7ade8b1..be015f02027f5 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -3422,12 +3422,18 @@ bool Sema::CheckRISCVBuiltinFunctionCall(const TargetInfo &TI,
   Features.split(ReqFeatures, ',');
 
   // Check if each required feature is included
-  for (auto &I : ReqFeatures) {
-    if (TI.hasFeature(I))
+  for (StringRef F : ReqFeatures) {
+    if (TI.hasFeature(F))
       continue;
+
+    // If the feature is 64bit, alter the string so it will print better in
+    // the diagnostic.
+    if (F == "64bit")
+      F = "RV64";
+
     // Convert features like "zbr" and "experimental-zbr" to "Zbr".
-    I.consume_front("experimental-");
-    std::string FeatureStr = I.str();
+    F.consume_front("experimental-");
+    std::string FeatureStr = F.str();
     FeatureStr[0] = std::toupper(FeatureStr[0]);
 
     // Error message

diff  --git a/clang/test/CodeGen/RISCV/rvb-intrinsics/riscv32-zbb-error.c b/clang/test/CodeGen/RISCV/rvb-intrinsics/riscv32-zbb-error.c
new file mode 100644
index 0000000000000..ad864aa65feff
--- /dev/null
+++ b/clang/test/CodeGen/RISCV/rvb-intrinsics/riscv32-zbb-error.c
@@ -0,0 +1,6 @@
+// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py
+// RUN: %clang_cc1 -triple riscv32 -target-feature +experimental-zbb -verify %s -o -
+
+int orc_b_64(int a) {
+  return __builtin_riscv_orc_b_64(a); // expected-error {{builtin requires 'RV64' extension support to be enabled}}
+}