Revert "[PPC64] Fix DQ-form instruction handling and emit error for misalign..."

This reverts commit 5125b44dbb5d06b715213e4bec75c7346bfcc7d3.
ppc64-dq.s and ppc64-error-missaligned-dq.s fail on several of the build-bots.
Reverting to investigate.

llvm-svn: 340568

4 files changed, 7 insertions, 119 deletions

diff --git a/lld/ELF/Arch/PPC64.cpp b/lld/ELF/Arch/PPC64.cpp
index 803b392eb8b..cf116828dbf 100644
--- a/lld/ELF/Arch/PPC64.cpp
+++ b/lld/ELF/Arch/PPC64.cpp
@@ -98,24 +98,6 @@ static uint16_t highera(uint64_t V) { return (V + 0x8000) >> 32; }
 static uint16_t highest(uint64_t V) { return V >> 48; }
 static uint16_t highesta(uint64_t V) { return (V + 0x8000) >> 48; }
 
-// Extracts the 'PO' field of an instruction encoding.
-static uint8_t getPrimaryOpCode(uint32_t Encoding) { return (Encoding >> 26); }
-
-static bool isDQFormInstruction(uint32_t Encoding) {
-  switch (getPrimaryOpCode(Encoding)) {
-  default:
-    return false;
-  case 56:
-    // The only instruction with a primary opcode of 56 is `lq`.
-    return true;
-  case 61:
-    // There are both DS and DQ instruction forms with this primary opcode.
-    // Namely `lxv` and `stxv` are the DQ-forms that use it.
-    // The DS 'XO' bits being set to 01 is restricted to DQ form.
-    return (Encoding & 3) == 0x1;
-  }
-}
-
 PPC64::PPC64() {
   GotRel = R_PPC64_GLOB_DAT;
   PltRel = R_PPC64_JMP_SLOT;
@@ -316,7 +298,7 @@ void PPC64::relaxTlsIeToLe(uint8_t *Loc, RelType Type, uint64_t Val) const {
     break;
   }
   case R_PPC64_TLS: {
-    uint32_t PrimaryOp = getPrimaryOpCode(read32(Loc));
+    uint32_t PrimaryOp = (read32(Loc) & 0xFC000000) >> 26; // bits 0-5
     if (PrimaryOp != 31)
       error("unrecognized instruction for IE to LE R_PPC64_TLS");
     uint32_t SecondaryOp = (read32(Loc) & 0x000007FE) >> 1; // bits 21-30
@@ -524,15 +506,10 @@ void PPC64::relocateOne(uint8_t *Loc, RelType Type, uint64_t Val) const {
     write16(Loc, Val);
     break;
   case R_PPC64_ADDR16_DS:
-  case R_PPC64_TPREL16_DS: {
+  case R_PPC64_TPREL16_DS:
     checkInt(Loc, Val, 16, Type);
-    // DQ-form instructions use bits 28-31 as part of the instruction encoding
-    // DS-form instructions only use bits 30-31.
-    uint32_t EndianOffset = Config->EKind == ELF64BEKind ? 2U : 0U;
-    uint16_t Mask = isDQFormInstruction(read32(Loc - EndianOffset)) ? 0xF : 0x3;
-    checkAlignment(Loc, lo(Val), Mask + 1, Type);
-    write16(Loc, (read16(Loc) & Mask) | lo(Val));
-  } break;
+    write16(Loc, (read16(Loc) & 3) | (Val & ~3));
+    break;
   case R_PPC64_ADDR16_HA:
   case R_PPC64_REL16_HA:
   case R_PPC64_TPREL16_HA:
@@ -565,14 +542,9 @@ void PPC64::relocateOne(uint8_t *Loc, RelType Type, uint64_t Val) const {
     write16(Loc, lo(Val));
     break;
   case R_PPC64_ADDR16_LO_DS:
-  case R_PPC64_TPREL16_LO_DS: {
-    // DQ-form instructions use bits 28-31 as part of the instruction encoding
-    // DS-form instructions only use bits 30-31.
-    uint32_t EndianOffset = Config->EKind == ELF64BEKind ? 2U : 0U;
-    uint16_t Mask = isDQFormInstruction(read32(Loc - EndianOffset)) ? 0xF : 0x3;
-    checkAlignment(Loc, lo(Val), Mask + 1, Type);
-    write16(Loc, (read16(Loc) & Mask) | lo(Val));
-  } break;
+  case R_PPC64_TPREL16_LO_DS:
+    write16(Loc, (read16(Loc) & 3) | (lo(Val) & ~3));
+    break;
   case R_PPC64_ADDR32:
   case R_PPC64_REL32:
     checkInt(Loc, Val, 32, Type);
diff --git a/lld/test/ELF/ppc64-dq.s b/lld/test/ELF/ppc64-dq.s
deleted file mode 100644
index 0fb8441a2d0..00000000000
--- a/lld/test/ELF/ppc64-dq.s
+++ /dev/null
@@ -1,32 +0,0 @@
-# REQUIRES: ppc
-
-# RUN: llvm-mc -filetype=obj -triple=powerpc64le-unknown-linux %s -o %t.o
-# RUN: ld.lld %t.o -o %t
-# RUN: llvm-objdump -D %t | FileCheck %s
-
-# RUN: llvm-mc -filetype=obj -triple=powerpc64-unknown-linux %s -o %t.o
-# RUN: ld.lld %t.o -o %t
-# RUN: llvm-objdump -D %t | FileCheck %s
-
-        .global test
-        .p2align        4
-        .type   test,@function
-test:
-.Lgep:
-        addis 2, 12, .TOC.-.Lgep@ha
-        addi  2, 2,  .TOC.-.Lgep@l
-.Llep:
-        .localentry test, .Llep-.Lgep
-        addis 3, 2, qword@toc@ha
-        lxv   3, qword@toc@l(3)
-        addis 3, 2, qword@toc@ha
-        stxv  3, qword@toc@l(3)
-        blr
-
-       .comm qword, 16, 16
-
-# Verify that we don't overwrite any of the extended opcode bits on a DQ form
-# instruction.
-# CHECK-LABEL: test
-# CHECK:         lxv 3, -32768(3)
-# CHECK:         stxv 3, -32768(3)
diff --git a/lld/test/ELF/ppc64-error-missaligned-dq.s b/lld/test/ELF/ppc64-error-missaligned-dq.s
deleted file mode 100644
index ea30ab88fb8..00000000000
--- a/lld/test/ELF/ppc64-error-missaligned-dq.s
+++ /dev/null
@@ -1,26 +0,0 @@
-# REQUIRES: ppc
-#
-# RUN: llvm-mc -filetype=obj -triple=powerpc64le-unknown-linux %s -o %t.o
-# RUN: not ld.lld %t.o -o %t 2>&1 | FileCheck %s
-
-# RUN: llvm-mc -filetype=obj -triple=powerpc64-unknown-linux %s -o %t.o
-# RUN: not ld.lld %t.o -o %t 2>&1 | FileCheck %s
-
-# CHECK: improper alignment for relocation R_PPC64_ADDR16_LO_DS: 0x8001 is not aligned to 16 bytes
-
-        .global test
-        .p2align        4
-        .type   test,@function
-test:
-.Lgep:
-        addis 2, 12, .TOC.-.Lgep@ha
-        addi  2, 2,  .TOC.-.Lgep@l
-.Llep:
-        .localentry test, .Llep-.Lgep
-        addis 3, 2, qword@toc@ha
-        lxv   3, qword@toc@l(3)
-        blr
-
-       .comm pad, 1, 1
-       .comm qword, 16, 1
-
diff --git a/lld/test/ELF/ppc64-error-missaligned-ds.s b/lld/test/ELF/ppc64-error-missaligned-ds.s
deleted file mode 100644
index 99a2c08bc99..00000000000
--- a/lld/test/ELF/ppc64-error-missaligned-ds.s
+++ /dev/null
@@ -1,26 +0,0 @@
-# REQUIRES: ppc
-
-# RUN: llvm-mc -filetype=obj -triple=powerpc64le-unknown-linux %s -o %t.o
-# RUN: not ld.lld %t.o -o %t 2>&1 | FileCheck %s
-
-# RUN: llvm-mc -filetype=obj -triple=powerpc64-unknown-linux %s -o %t.o
-# RUN: not ld.lld %t.o -o %t 2>&1 | FileCheck %s
-
-# CHECK: improper alignment for relocation R_PPC64_ADDR16_LO_DS: 0x8001 is not aligned to 4 bytes
-
-        .global test
-        .p2align        4
-        .type   test,@function
-test:
-.Lgep:
-        addis 2, 12, .TOC.-.Lgep@ha
-        addi  2, 2,  .TOC.-.Lgep@l
-.Llep:
-        .localentry test, .Llep-.Lgep
-        addis 3, 2, word@toc@ha
-        lwa   3, word@toc@l(3)
-        blr
-
-       .comm pad, 1, 1
-       .comm word, 4, 1
-