[mips] Correct ELF e_flags for the N32 ABI when using a mips-* triple rather than a mips64-* triple

Summary:
Generally speaking, mips-* vs mips64-* should not be used to make decisions
about the content or format of the ELF. This should be based on the ABI
and CPU in use. For example, `mips-linux-gnu-clang -mips64r2 -mabi=64`
should produce an ELF64 as should `mips64-linux-gnu-clang -mabi=64`.
Conversely, `mips64-linux-gnu-clang -mabi=n32` should produce an ELF32 as
should `mips-linux-gnu-clang -mips64r2 -mabi=n32`.

This patch fixes the e_flags but leaves the ELF32 vs ELF64 issue for now
since there is no apparent way to base this decision on the ABI and CPU.

Differential Revision: http://reviews.llvm.org/D4539

llvm-svn: 213244

2 files changed, 18 insertions, 21 deletions

diff --git a/llvm/lib/Target/Mips/MCTargetDesc/MipsTargetStreamer.cpp b/llvm/lib/Target/Mips/MCTargetDesc/MipsTargetStreamer.cpp
index 3aa4027613b..e017a27d6b9 100644
--- a/llvm/lib/Target/Mips/MCTargetDesc/MipsTargetStreamer.cpp
+++ b/llvm/lib/Target/Mips/MCTargetDesc/MipsTargetStreamer.cpp
@@ -281,22 +281,18 @@ MipsTargetELFStreamer::MipsTargetELFStreamer(MCStreamer &S,
   else
     EFlags |= ELF::EF_MIPS_ARCH_1;
 
-  if (T.isArch64Bit()) {
-    if (Features & Mips::FeatureN32)
-      EFlags |= ELF::EF_MIPS_ABI2;
-    else if (Features & Mips::FeatureO32) {
-      EFlags |= ELF::EF_MIPS_ABI_O32;
-      EFlags |= ELF::EF_MIPS_32BITMODE; /* Compatibility Mode */
-    }
-    // No need to set any bit for N64 which is the default ABI at the moment
-    // for 64-bit Mips architectures.
-  } else {
-    if (Features & Mips::FeatureMips64r2 || Features & Mips::FeatureMips64)
-      EFlags |= ELF::EF_MIPS_32BITMODE;
-
-    // ABI
+  // ABI
+  // N64 does not require any ABI bits.
+  if (Features & Mips::FeatureO32)
     EFlags |= ELF::EF_MIPS_ABI_O32;
-  }
+  else if (Features & Mips::FeatureN32)
+    EFlags |= ELF::EF_MIPS_ABI2;
+
+  if (Features & Mips::FeatureGP64Bit) {
+    if (Features & Mips::FeatureO32)
+      EFlags |= ELF::EF_MIPS_32BITMODE; /* Compatibility Mode */
+  } else if (Features & Mips::FeatureMips64r2 || Features & Mips::FeatureMips64)
+    EFlags |= ELF::EF_MIPS_32BITMODE;
 
   // Other options.
   if (Features & Mips::FeatureNaN2008)
diff --git a/llvm/test/MC/Mips/elf_eflags.s b/llvm/test/MC/Mips/elf_eflags.s
index 9e742d71383..1f28ee0ff89 100644
--- a/llvm/test/MC/Mips/elf_eflags.s
+++ b/llvm/test/MC/Mips/elf_eflags.s
@@ -2,22 +2,22 @@
 # corresponding options (-mcpu=mips32 -> -mips32 for example).
 
 # RUN: llvm-mc -filetype=obj -triple mipsel-unknown-linux -mcpu=mips64r6 %s -o -| llvm-readobj -h | FileCheck --check-prefix=MIPSEL-MIPS64R6 %s
-# MIPSEL-MIPS64R6: Flags [ (0xA0001506)
+# MIPSEL-MIPS64R6: Flags [ (0xA0000406)
 
 # RUN: llvm-mc -filetype=obj -triple mipsel-unknown-linux -mcpu=mips64r6 -mattr=+nan2008 %s -o -| llvm-readobj -h | FileCheck --check-prefix=MIPSEL-MIPS64R6-NAN2008 %s
-# MIPSEL-MIPS64R6-NAN2008: Flags [ (0xA0001506)
+# MIPSEL-MIPS64R6-NAN2008: Flags [ (0xA0000406)
 
 # RUN: llvm-mc -filetype=obj -triple mipsel-unknown-linux -mcpu=mips64r2 %s -o -| llvm-readobj -h | FileCheck --check-prefix=MIPSEL-MIPS64R2 %s
-# MIPSEL-MIPS64R2: Flags [ (0x80001106)
+# MIPSEL-MIPS64R2: Flags [ (0x80000006)
 
 # RUN: llvm-mc -filetype=obj -triple mipsel-unknown-linux -mcpu=mips64r2 -mattr=+nan2008 %s -o -| llvm-readobj -h | FileCheck --check-prefix=MIPSEL-MIPS64R2-NAN2008 %s
-# MIPSEL-MIPS64R2-NAN2008: Flags [ (0x80001506)
+# MIPSEL-MIPS64R2-NAN2008: Flags [ (0x80000406)
 
 # RUN: llvm-mc -filetype=obj -triple mipsel-unknown-linux -mcpu=mips64 %s -o -| llvm-readobj -h | FileCheck --check-prefix=MIPSEL-MIPS64 %s
-# MIPSEL-MIPS64: Flags [ (0x60001106)
+# MIPSEL-MIPS64: Flags [ (0x60000006)
 
 # RUN: llvm-mc -filetype=obj -triple mipsel-unknown-linux -mcpu=mips64 -mattr=+nan2008 %s -o -| llvm-readobj -h | FileCheck --check-prefix=MIPSEL-MIPS64-NAN2008 %s
-# MIPSEL-MIPS64-NAN2008: Flags [ (0x60001506)
+# MIPSEL-MIPS64-NAN2008: Flags [ (0x60000406)
 
 # RUN: llvm-mc -filetype=obj -triple mipsel-unknown-linux -mcpu=mips32r6 %s -o -| llvm-readobj -h | FileCheck --check-prefix=MIPSEL-MIPS32R6 %s
 # MIPSEL-MIPS32R6: Flags [ (0x90001404)
@@ -37,6 +37,7 @@
 # RUN: llvm-mc -filetype=obj -triple mipsel-unknown-linux -mcpu=mips32 -mattr=+nan2008 %s -o -| llvm-readobj -h | FileCheck --check-prefix=MIPSEL-MIPS32-NAN2008 %s
 # MIPSEL-MIPS32-NAN2008: Flags [ (0x50001404)
 
+# RUN: llvm-mc -filetype=obj -triple mipsel-unknown-linux -mcpu=mips64r2 -mattr=-n64,n32 %s -o -| llvm-readobj -h | FileCheck --check-prefix=MIPS64EL-MIPS64R2-N32 %s
 # RUN: llvm-mc -filetype=obj -triple mips64el-unknown-linux -mcpu=mips64r2 -mattr=-n64,n32 %s -o -| llvm-readobj -h | FileCheck --check-prefix=MIPS64EL-MIPS64R2-N32 %s
 # MIPS64EL-MIPS64R2-N32: Flags [ (0x80000024)