[mips] Work around inconsistency in llvm-mc's placement of fixup markers

Summary:
Add a second fixup table to MipsAsmBackend::getFixupKindInfo() to correctly
position llvm-mc's fixup placeholders for big-endian.

See PR19836 for full details of the issue. To summarize, the fixup placeholders
do not account for endianness properly and the implementations of
getFixupKindInfo() for each target are measuring MCFixupKindInfo.TargetOffset
from different ends of the instruction encoding to compensate.

Reviewers: jkolek, zoran.jovanovic, vmedic

Reviewed By: vmedic

Differential Revision: http://reviews.llvm.org/D3889

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209514 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/Mips/MCTargetDesc/MipsAsmBackend.cpp b/lib/Target/Mips/MCTargetDesc/MipsAsmBackend.cpp
index 153974e470f9456fd0dff874319844e4abf7a725..332f7ea7a261764878bf7cbfdbd5060ba8e7a618 100644 (file)
--- a/lib/Target/Mips/MCTargetDesc/MipsAsmBackend.cpp
+++ b/lib/Target/Mips/MCTargetDesc/MipsAsmBackend.cpp
@@ -189,7 +189,7 @@ void MipsAsmBackend::applyFixup(const MCFixup &Fixup, char *Data,
 
 const MCFixupKindInfo &MipsAsmBackend::
 getFixupKindInfo(MCFixupKind Kind) const {
-  const static MCFixupKindInfo Infos[Mips::NumTargetFixupKinds] = {
+  const static MCFixupKindInfo LittleEndianInfos[Mips::NumTargetFixupKinds] = {
     // This table *must* be in same the order of fixup_* kinds in
     // MipsFixupKinds.h.
     //
@@ -246,12 +246,72 @@ getFixupKindInfo(MCFixupKind Kind) const {
     { "fixup_MICROMIPS_TLS_TPREL_LO16",  0,     16,   0 }
   };
 
+  const static MCFixupKindInfo BigEndianInfos[Mips::NumTargetFixupKinds] = {
+    // This table *must* be in same the order of fixup_* kinds in
+    // MipsFixupKinds.h.
+    //
+    // name                    offset  bits  flags
+    { "fixup_Mips_16",          16,     16,   0 },
+    { "fixup_Mips_32",           0,     32,   0 },
+    { "fixup_Mips_REL32",        0,     32,   0 },
+    { "fixup_Mips_26",           6,     26,   0 },
+    { "fixup_Mips_HI16",        16,     16,   0 },
+    { "fixup_Mips_LO16",        16,     16,   0 },
+    { "fixup_Mips_GPREL16",     16,     16,   0 },
+    { "fixup_Mips_LITERAL",     16,     16,   0 },
+    { "fixup_Mips_GOT_Global",  16,     16,   0 },
+    { "fixup_Mips_GOT_Local",   16,     16,   0 },
+    { "fixup_Mips_PC16",        16,     16,  MCFixupKindInfo::FKF_IsPCRel },
+    { "fixup_Mips_CALL16",      16,     16,   0 },
+    { "fixup_Mips_GPREL32",      0,     32,   0 },
+    { "fixup_Mips_SHIFT5",      21,      5,   0 },
+    { "fixup_Mips_SHIFT6",      21,      5,   0 },
+    { "fixup_Mips_64",           0,     64,   0 },
+    { "fixup_Mips_TLSGD",       16,     16,   0 },
+    { "fixup_Mips_GOTTPREL",    16,     16,   0 },
+    { "fixup_Mips_TPREL_HI",    16,     16,   0 },
+    { "fixup_Mips_TPREL_LO",    16,     16,   0 },
+    { "fixup_Mips_TLSLDM",      16,     16,   0 },
+    { "fixup_Mips_DTPREL_HI",   16,     16,   0 },
+    { "fixup_Mips_DTPREL_LO",   16,     16,   0 },
+    { "fixup_Mips_Branch_PCRel",16,     16,  MCFixupKindInfo::FKF_IsPCRel },
+    { "fixup_Mips_GPOFF_HI",    16,     16,   0 },
+    { "fixup_Mips_GPOFF_LO",    16,     16,   0 },
+    { "fixup_Mips_GOT_PAGE",    16,     16,   0 },
+    { "fixup_Mips_GOT_OFST",    16,     16,   0 },
+    { "fixup_Mips_GOT_DISP",    16,     16,   0 },
+    { "fixup_Mips_HIGHER",      16,     16,   0 },
+    { "fixup_Mips_HIGHEST",     16,     16,   0 },
+    { "fixup_Mips_GOT_HI16",    16,     16,   0 },
+    { "fixup_Mips_GOT_LO16",    16,     16,   0 },
+    { "fixup_Mips_CALL_HI16",   16,     16,   0 },
+    { "fixup_Mips_CALL_LO16",   16,     16,   0 },
+    { "fixup_MICROMIPS_26_S1",   6,     26,   0 },
+    { "fixup_MICROMIPS_HI16",   16,     16,   0 },
+    { "fixup_MICROMIPS_LO16",   16,     16,   0 },
+    { "fixup_MICROMIPS_GOT16",  16,     16,   0 },
+    { "fixup_MICROMIPS_PC16_S1",16,     16,   MCFixupKindInfo::FKF_IsPCRel },
+    { "fixup_MICROMIPS_CALL16", 16,     16,   0 },
+    { "fixup_MICROMIPS_GOT_DISP",        16,     16,   0 },
+    { "fixup_MICROMIPS_GOT_PAGE",        16,     16,   0 },
+    { "fixup_MICROMIPS_GOT_OFST",        16,     16,   0 },
+    { "fixup_MICROMIPS_TLS_GD",          16,     16,   0 },
+    { "fixup_MICROMIPS_TLS_LDM",         16,     16,   0 },
+    { "fixup_MICROMIPS_TLS_DTPREL_HI16", 16,     16,   0 },
+    { "fixup_MICROMIPS_TLS_DTPREL_LO16", 16,     16,   0 },
+    { "fixup_MICROMIPS_TLS_TPREL_HI16",  16,     16,   0 },
+    { "fixup_MICROMIPS_TLS_TPREL_LO16",  16,     16,   0 }
+  };
+
   if (Kind < FirstTargetFixupKind)
     return MCAsmBackend::getFixupKindInfo(Kind);
 
   assert(unsigned(Kind - FirstTargetFixupKind) < getNumFixupKinds() &&
           "Invalid kind!");
-  return Infos[Kind - FirstTargetFixupKind];
+
+  if (IsLittle)
+    return LittleEndianInfos[Kind - FirstTargetFixupKind];
+  return BigEndianInfos[Kind - FirstTargetFixupKind];
 }
 
 /// WriteNopData - Write an (optimal) nop sequence of Count bytes

diff --git a/test/MC/Mips/llvm-mc-fixup-endianness.s b/test/MC/Mips/llvm-mc-fixup-endianness.s
new file mode 100644 (file)
index 0000000..bc6a5d9
--- /dev/null
+++ b/test/MC/Mips/llvm-mc-fixup-endianness.s
@@ -0,0 +1,6 @@
+# RUN: llvm-mc -show-encoding -mcpu=mips32 -triple mips-unknown-unknown %s | FileCheck -check-prefix=BE %s
+# RUN: llvm-mc -show-encoding -mcpu=mips32 -triple mipsel-unknown-unknown %s | FileCheck -check-prefix=LE %s
+#
+        .text
+        b foo # BE: b foo # encoding: [0x10,0x00,A,A]
+              # LE: b foo # encoding: [A,A,0x00,0x10]

diff --git a/test/MC/Mips/mips_directives.s b/test/MC/Mips/mips_directives.s
index 6780dd0b3ca5128d03240a616d52cbee6424f76f..1a7d61f3ad4fb1581a30aa5c5a6408189b435da2 100644 (file)
--- a/test/MC/Mips/mips_directives.s
+++ b/test/MC/Mips/mips_directives.s
@@ -51,7 +51,7 @@ $BB0_4:
     .set  $tmp7, $BB0_4-$BB0_2
     .set f6,$f6
 # CHECK:    abs.s   $f6, $f7           # encoding: [0x46,0x00,0x39,0x85]
-# CHECK:    lui     $1, %hi($tmp7)     # encoding: [0x3c'A',0x01'A',0x00,0x00]
+# CHECK:    lui     $1, %hi($tmp7)     # encoding: [0x3c,0x01,A,A]
 # CHECK:                               #   fixup A - offset: 0, value: ($tmp7)@ABS_HI, kind: fixup_Mips_HI16
     abs.s  f6,FPU_MASK
     lui $1, %hi($tmp7)

diff --git a/test/MC/Mips/mips_gprel16.s b/test/MC/Mips/mips_gprel16.s
index 716c75ec88d456ed97d320d16c0174d6ce222b44..9dd3fa3281c21ffd3a92274b2c7489dfbbbf65b2 100644 (file)
--- a/test/MC/Mips/mips_gprel16.s
+++ b/test/MC/Mips/mips_gprel16.s
@@ -5,6 +5,9 @@
 
 // RUN: llvm-mc -mcpu=mips32r2 -triple=mipsel-pc-linux -filetype=obj -relocation-model=static %s -o - \
 // RUN: | llvm-objdump -disassemble -mattr +mips32r2 - \
+// RUN: | FileCheck %s
+// RUN: llvm-mc -mcpu=mips32r2 -triple=mips-pc-linux -filetype=obj -relocation-model=static %s -o - \
+// RUN: | llvm-objdump -disassemble -mattr +mips32r2 - \
 // RUN: | FileCheck %s
 
        .text

diff --git a/test/MC/Mips/msa/test_cbranch.s b/test/MC/Mips/msa/test_cbranch.s
index 37b88725602911002bbd3190130817bccfdf61e8..aa6779b1b46efb3d976a6fbf6d02bc6e24508aa4 100644 (file)
--- a/test/MC/Mips/msa/test_cbranch.s
+++ b/test/MC/Mips/msa/test_cbranch.s
@@ -7,22 +7,22 @@
 #CHECK:      bnz.w        $w2, 128      # encoding: [0x47,0xc2,0x00,0x20]
 #CHECK:      nop                        # encoding: [0x00,0x00,0x00,0x00]
 #CHECK:      bnz.d        $w3, -128     # encoding: [0x47,0xe3,0xff,0xe0]
-#CHECK:      bnz.b        $w0, SYMBOL0  # encoding: [0x47'A',0x80'A',0x00,0x00]
+#CHECK:      bnz.b        $w0, SYMBOL0  # encoding: [0x47,0x80,A,A]
                                         #   fixup A - offset: 0, value: SYMBOL0, kind: fixup_Mips_PC16
 #CHECK:      nop                        # encoding: [0x00,0x00,0x00,0x00]
-#CHECK:      bnz.h        $w1, SYMBOL1  # encoding: [0x47'A',0xa1'A',0x00,0x00]
+#CHECK:      bnz.h        $w1, SYMBOL1  # encoding: [0x47,0xa1,A,A]
                                         #   fixup A - offset: 0, value: SYMBOL1, kind: fixup_Mips_PC16
 #CHECK:      nop                        # encoding: [0x00,0x00,0x00,0x00]
-#CHECK:      bnz.w        $w2, SYMBOL2  # encoding: [0x47'A',0xc2'A',0x00,0x00]
+#CHECK:      bnz.w        $w2, SYMBOL2  # encoding: [0x47,0xc2,A,A]
                                         #   fixup A - offset: 0, value: SYMBOL2, kind: fixup_Mips_PC16
 #CHECK:      nop                        # encoding: [0x00,0x00,0x00,0x00]
-#CHECK:      bnz.d        $w3, SYMBOL3  # encoding: [0x47'A',0xe3'A',0x00,0x00]
+#CHECK:      bnz.d        $w3, SYMBOL3  # encoding: [0x47,0xe3,A,A]
                                         #   fixup A - offset: 0, value: SYMBOL3, kind: fixup_Mips_PC16
 #CHECK:      nop                        # encoding: [0x00,0x00,0x00,0x00]
 
 #CHECK:      bnz.v        $w0, 4        # encoding: [0x45,0xe0,0x00,0x01]
 #CHECK:      nop                        # encoding: [0x00,0x00,0x00,0x00]
-#CHECK:      bnz.v        $w0, SYMBOL0  # encoding: [0x45'A',0xe0'A',0x00,0x00]
+#CHECK:      bnz.v        $w0, SYMBOL0  # encoding: [0x45,0xe0,A,A]
                                         #   fixup A - offset: 0, value: SYMBOL0, kind: fixup_Mips_PC16
 #CHECK:      nop                        # encoding: [0x00,0x00,0x00,0x00]
 
@@ -34,22 +34,22 @@
 #CHECK:      nop                        # encoding: [0x00,0x00,0x00,0x00]
 #CHECK:      bz.d         $w3, -1024    # encoding: [0x47,0x63,0xff,0x00]
 #CHECK:      nop                        # encoding: [0x00,0x00,0x00,0x00]
-#CHECK:      bz.b         $w0, SYMBOL0  # encoding: [0x47'A',A,0x00,0x00]
+#CHECK:      bz.b         $w0, SYMBOL0  # encoding: [0x47,0x00,A,A]
                                         #   fixup A - offset: 0, value: SYMBOL0, kind: fixup_Mips_PC16
 #CHECK:      nop                        # encoding: [0x00,0x00,0x00,0x00]
-#CHECK:      bz.h         $w1, SYMBOL1  # encoding: [0x47'A',0x21'A',0x00,0x00]
+#CHECK:      bz.h         $w1, SYMBOL1  # encoding: [0x47,0x21,A,A]
                                         #   fixup A - offset: 0, value: SYMBOL1, kind: fixup_Mips_PC16
 #CHECK:      nop                        # encoding: [0x00,0x00,0x00,0x00]
-#CHECK:      bz.w         $w2, SYMBOL2  # encoding: [0x47'A',0x42'A',0x00,0x00]
+#CHECK:      bz.w         $w2, SYMBOL2  # encoding: [0x47,0x42,A,A]
                                         #   fixup A - offset: 0, value: SYMBOL2, kind: fixup_Mips_PC16
 #CHECK:      nop                        # encoding: [0x00,0x00,0x00,0x00]
-#CHECK:      bz.d         $w3, SYMBOL3  # encoding: [0x47'A',0x63'A',0x00,0x00]
+#CHECK:      bz.d         $w3, SYMBOL3  # encoding: [0x47,0x63,A,A]
                                         #   fixup A - offset: 0, value: SYMBOL3, kind: fixup_Mips_PC16
 #CHECK:      nop                        # encoding: [0x00,0x00,0x00,0x00]
 
 #CHECK:      bz.v        $w0, 4        # encoding: [0x45,0x60,0x00,0x01]
 #CHECK:      nop                       # encoding: [0x00,0x00,0x00,0x00]
-#CHECK:      bz.v        $w0, SYMBOL0  # encoding: [0x45'A',0x60'A',0x00,0x00]
+#CHECK:      bz.v        $w0, SYMBOL0  # encoding: [0x45,0x60,A,A]
                                        #   fixup A - offset: 0, value: SYMBOL0, kind: fixup_Mips_PC16
 #CHECK:      nop                       # encoding: [0x00,0x00,0x00,0x00]