From 7cfded350a7edc87f4a67f84e4261e44954600d0 Mon Sep 17 00:00:00 2001
From: Lei Huang <lei@ca.ibm.com>
Date: Thu, 28 May 2020 15:30:47 -0500
Subject: [PATCH] [PowerPC] Add clang option -m[no-]pcrel

Summary:
Add user-facing front end option to turn off pc-relative memops.
This will be compatible with gcc.

Reviewers: stefanp, nemanjai, hfinkel, power-llvm-team, #powerpc, NeHuang, saghir

Reviewed By: stefanp, NeHuang, saghir

Subscribers: saghir, wuzish, shchenz, cfe-commits, kbarton, echristo

Tags: #clang, #powerpc

Differential Revision: https://reviews.llvm.org/D80757
---
 clang/include/clang/Driver/Options.td |  2 ++
 clang/lib/Basic/Targets/PPC.cpp       | 14 ++++++++++++--
 clang/lib/Basic/Targets/PPC.h         |  1 +
 clang/test/Driver/ppc-pcrel.cpp       | 12 ++++++++++++
 4 files changed, 27 insertions(+), 2 deletions(-)
 create mode 100644 clang/test/Driver/ppc-pcrel.cpp

diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index 729cbfb..0bbeeaf 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -2470,6 +2470,8 @@ def faltivec : Flag<["-"], "faltivec">, Group<f_Group>, Flags<[DriverOption]>;
 def fno_altivec : Flag<["-"], "fno-altivec">, Group<f_Group>, Flags<[DriverOption]>;
 def maltivec : Flag<["-"], "maltivec">, Group<m_ppc_Features_Group>;
 def mno_altivec : Flag<["-"], "mno-altivec">, Group<m_ppc_Features_Group>;
+def mpcrel: Flag<["-"], "mpcrel">, Group<m_ppc_Features_Group>;
+def mno_pcrel: Flag<["-"], "mno-pcrel">, Group<m_ppc_Features_Group>;
 def mspe : Flag<["-"], "mspe">, Group<m_ppc_Features_Group>;
 def mno_spe : Flag<["-"], "mno-spe">, Group<m_ppc_Features_Group>;
 def mvsx : Flag<["-"], "mvsx">, Group<m_ppc_Features_Group>;
diff --git a/clang/lib/Basic/Targets/PPC.cpp b/clang/lib/Basic/Targets/PPC.cpp
index ad34c28..230548d 100644
--- a/clang/lib/Basic/Targets/PPC.cpp
+++ b/clang/lib/Basic/Targets/PPC.cpp
@@ -54,6 +54,8 @@ bool PPCTargetInfo::handleTargetFeatures(std::vector<std::string> &Features,
       HasFloat128 = true;
     } else if (Feature == "+power9-vector") {
       HasP9Vector = true;
+    } else if (Feature == "+pcrelative-memops") {
+      HasPCRelativeMemops = true;
     } else if (Feature == "+spe") {
       HasSPE = true;
       LongDoubleWidth = LongDoubleAlign = 64;
@@ -346,6 +348,7 @@ bool PPCTargetInfo::initFeatureMap(
 void PPCTargetInfo::addP10SpecificFeatures(
     llvm::StringMap<bool> &Features) const {
   Features["htm"] = false; // HTM was removed for P10.
+  Features["pcrelative-memops"] = true;
   return;
 }
 
@@ -369,6 +372,7 @@ bool PPCTargetInfo::hasFeature(StringRef Feature) const {
       .Case("extdiv", HasExtDiv)
       .Case("float128", HasFloat128)
       .Case("power9-vector", HasP9Vector)
+      .Case("pcrelative-memops", HasPCRelativeMemops)
       .Case("spe", HasSPE)
       .Default(false);
 }
@@ -389,7 +393,10 @@ void PPCTargetInfo::setFeatureEnabled(llvm::StringMap<bool> &Features,
       Features["vsx"] = Features["altivec"] = true;
     if (Name == "power9-vector")
       Features["power8-vector"] = true;
-    Features[Name] = true;
+    if (Name == "pcrel")
+      Features["pcrelative-memops"] = true;
+    else
+      Features[Name] = true;
   } else {
     // If we're disabling altivec or vsx go ahead and disable all of the vsx
     // features.
@@ -398,7 +405,10 @@ void PPCTargetInfo::setFeatureEnabled(llvm::StringMap<bool> &Features,
           Features["float128"] = Features["power9-vector"] = false;
     if (Name == "power8-vector")
       Features["power9-vector"] = false;
-    Features[Name] = false;
+    if (Name == "pcrel")
+      Features["pcrelative-memops"] = false;
+    else
+      Features[Name] = false;
   }
 }
 
diff --git a/clang/lib/Basic/Targets/PPC.h b/clang/lib/Basic/Targets/PPC.h
index 691fa5f..9c0a7bd 100644
--- a/clang/lib/Basic/Targets/PPC.h
+++ b/clang/lib/Basic/Targets/PPC.h
@@ -69,6 +69,7 @@ class LLVM_LIBRARY_VISIBILITY PPCTargetInfo : public TargetInfo {
   bool HasExtDiv = false;
   bool HasP9Vector = false;
   bool HasSPE = false;
+  bool HasPCRelativeMemops = false;
 
 protected:
   std::string ABI;
diff --git a/clang/test/Driver/ppc-pcrel.cpp b/clang/test/Driver/ppc-pcrel.cpp
new file mode 100644
index 0000000..2b12f0d
--- /dev/null
+++ b/clang/test/Driver/ppc-pcrel.cpp
@@ -0,0 +1,12 @@
+// RUN: %clang -target powerpc64-unknown-linux-gnu %s -### -mcpu=pwr10 -mpcrel -o %t.o 2>&1 | FileCheck -check-prefix=CHECK-PCREL %s
+// RUN: %clang -target powerpc64-unknown-linux-gnu %s -### -mcpu=pwr10 -mno-pcrel -o %t.o 2>&1 | FileCheck -check-prefix=CHECK-NOPCREL %s
+// CHECK-NOPCREL: "-target-feature" "-pcrel"
+// CHECK-PCREL: "-target-feature" "+pcrel"
+
+// RUN: %clang -target powerpc64-unknown-linux-gnu -mcpu=pwr10 -emit-llvm -S %s -o - | grep "attributes.*+pcrelative-memops"
+// RUN: %clang -target powerpc64-unknown-linux-gnu -mcpu=pwr10 -mpcrel -emit-llvm -S %s -o - | grep "attributes.*+pcrelative-memops"
+// RUN: %clang -target powerpc64-unknown-linux-gnu -mcpu=pwr10 -mno-pcrel -emit-llvm -S %s -o - | grep "attributes.*\-pcrelative-memops"
+
+int main(int argc, char *argv[]) {
+  return 0;
+}
-- 
2.7.4