From f27e752fe888f8a8fd38d7e65854f57040a13160 Mon Sep 17 00:00:00 2001
From: Reid Kleckner <rnk@google.com>
Date: Mon, 1 Feb 2016 18:58:24 +0000
Subject: [PATCH] Fix attribute((mode([word|unwind_word]))) for x32

Patch by H.J. Lu

```
typedef unsigned int gcc_word __attribute__((mode(word)));
```
and

```
typedef unsigned int gcc_unwind_word __attribute__((mode(unwind_word)));
```
define the largest unsigned integer types which can be stored in a
general purpose register, which may not be the pointer type.  For x32,
they aren't pointer nor unsigned long.  We should

1. Make getUnwindWordWidth and getRegisterWidth virtual,
2. Override them for x32, similar to hasInt128Type.
3. Use getRegisterWidth for __attribute__((mode(word)));

This fixes PR 24706.

Reviewers: rnk

Differential Revision: http://reviews.llvm.org/D16779

llvm-svn: 259383
---
 clang/include/clang/Basic/TargetInfo.h |  4 ++--
 clang/lib/Basic/Targets.cpp            |  2 ++
 clang/lib/Sema/SemaDeclAttr.cpp        |  2 +-
 clang/test/Sema/attr-mode.c            | 11 +++++++++++
 4 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/clang/include/clang/Basic/TargetInfo.h b/clang/include/clang/Basic/TargetInfo.h
index f1d8338..69aab0e 100644
--- a/clang/include/clang/Basic/TargetInfo.h
+++ b/clang/include/clang/Basic/TargetInfo.h
@@ -413,10 +413,10 @@ public:
   }
 
   // Return the size of unwind_word for this target.
-  unsigned getUnwindWordWidth() const { return getPointerWidth(0); }
+  virtual unsigned getUnwindWordWidth() const { return getPointerWidth(0); }
 
   /// \brief Return the "preferred" register width on this target.
-  unsigned getRegisterWidth() const {
+  virtual unsigned getRegisterWidth() const {
     // Currently we assume the register width on the target matches the pointer
     // width, we can introduce a new variable for this if/when some target wants
     // it.
diff --git a/clang/lib/Basic/Targets.cpp b/clang/lib/Basic/Targets.cpp
index d75aa3e..3f4c1aa 100644
--- a/clang/lib/Basic/Targets.cpp
+++ b/clang/lib/Basic/Targets.cpp
@@ -4029,6 +4029,8 @@ public:
 
   // for x32 we need it here explicitly
   bool hasInt128Type() const override { return true; }
+  unsigned getUnwindWordWidth() const override { return 64; }
+  unsigned getRegisterWidth() const override { return 64; }
 
   bool validateGlobalRegisterVariable(StringRef RegName,
                                       unsigned RegSize,
diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp
index b216996..eb8a49c 100644
--- a/clang/lib/Sema/SemaDeclAttr.cpp
+++ b/clang/lib/Sema/SemaDeclAttr.cpp
@@ -3332,7 +3332,7 @@ static void parseModeAttrArg(Sema &S, StringRef Str, unsigned &DestWidth,
     // FIXME: glibc uses 'word' to define register_t; this is narrower than a
     // pointer on PIC16 and other embedded platforms.
     if (Str == "word")
-      DestWidth = S.Context.getTargetInfo().getPointerWidth(0);
+      DestWidth = S.Context.getTargetInfo().getRegisterWidth();
     else if (Str == "byte")
       DestWidth = S.Context.getTargetInfo().getCharWidth();
     break;
diff --git a/clang/test/Sema/attr-mode.c b/clang/test/Sema/attr-mode.c
index 179b181..405bfb7 100644
--- a/clang/test/Sema/attr-mode.c
+++ b/clang/test/Sema/attr-mode.c
@@ -4,6 +4,8 @@
 // RUN:   -verify %s
 // RUN: %clang_cc1 -triple powerpc64-pc-linux-gnu -DTEST_64BIT_PPC64 -fsyntax-only \
 // RUN:   -verify %s
+// RUN: %clang_cc1 -triple x86_64-pc-linux-gnux32 -DTEST_64BIT_X86 -fsyntax-only \
+// RUN:   -verify %s
 
 typedef int i16_1 __attribute((mode(HI)));
 int i16_1_test[sizeof(i16_1) == 2 ? 1 : -1];
@@ -63,8 +65,17 @@ void test_int_to_ui32(unsigned int* y) { f_ui32_arg(y); }
 void test_long_to_i64(long long* y) { f_i64_arg(y); }
 void test_long_to_ui64(unsigned long long* y) { f_ui64_arg(y); }
 #elif TEST_64BIT_X86
+#ifdef __ILP32__
+typedef unsigned int gcc_word __attribute__((mode(word)));
+int foo[sizeof(gcc_word) == 8 ? 1 : -1];
+typedef unsigned int gcc_unwind_word __attribute__((mode(unwind_word)));
+int foo[sizeof(gcc_unwind_word) == 8 ? 1 : -1];
+void test_long_to_i64(long long* y) { f_i64_arg(y); }
+void test_long_to_ui64(unsigned long long* y) { f_ui64_arg(y); }
+#else
 void test_long_to_i64(long* y) { f_i64_arg(y); }
 void test_long_to_ui64(unsigned long* y) { f_ui64_arg(y); }
+#endif
 typedef          float f128ibm __attribute__ ((mode (TF)));     // expected-error{{unsupported machine mode 'TF'}}
 #elif TEST_64BIT_PPC64
 typedef          float f128ibm __attribute__ ((mode (TF)));
-- 
2.7.4