[lld] 321b2be - [lld-macho] Use DO_BIND_ADD_ADDR_IMM_SCALED for bind opcodes
Vincent Lee via llvm-commits
llvm-commits at lists.llvm.org
Mon Jul 19 16:19:01 PDT 2021
Author: Vincent Lee
Date: 2021-07-19T16:18:33-07:00
New Revision: 321b2bef098553ec648e4174aae92c63a6e1a810
URL: https://github.com/llvm/llvm-project/commit/321b2bef098553ec648e4174aae92c63a6e1a810
DIFF: https://github.com/llvm/llvm-project/commit/321b2bef098553ec648e4174aae92c63a6e1a810.diff
LOG: [lld-macho] Use DO_BIND_ADD_ADDR_IMM_SCALED for bind opcodes
Implement pass 3 of bind opcodes from ld64 (which supports both 32-bit and 64-bit).
Pass 3 implementation condenses BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB opcode
to BIND_OPCODE_DO_BIND_ADD_ADDR_IMM_SCALED. This change is already behind an
O2 flag so it shouldn't impact current performance. I verified ld64's output with x86_64 LLD
and they were both emitting the same optimized bind opcodes (although in a slightly different
order). Tested with arm64_32 LLD and compared that with x86 LLD that the order of the bind
opcodes are the same (offset values are different which should be expected).
Reviewed By: int3, #lld-macho
Differential Revision: https://reviews.llvm.org/D106128
Added:
Modified:
lld/MachO/SyntheticSections.cpp
lld/test/MachO/bind-opcodes.s
Removed:
################################################################################
diff --git a/lld/MachO/SyntheticSections.cpp b/lld/MachO/SyntheticSections.cpp
index d65cc9c3ced2..47a9b2b6c608 100644
--- a/lld/MachO/SyntheticSections.cpp
+++ b/lld/MachO/SyntheticSections.cpp
@@ -360,6 +360,23 @@ static void optimizeOpcodes(std::vector<BindIR> &opcodes) {
if (i == opcodes.size())
opcodes[pWrite] = opcodes[i - 1];
opcodes.resize(pWrite + 1);
+
+ // Pass 3: Use immediate encodings
+ // Every binding is the size of one pointer. If the next binding is a
+ // multiple of wordSize away that is within BIND_IMMEDIATE_MASK, the
+ // opcode can be scaled by wordSize into a single byte and dyld will
+ // expand it to the correct address.
+ for (BindIR *p = &opcodes[0]; p->opcode != BIND_OPCODE_DONE; ++p) {
+ // It's unclear why the check needs to be less than BIND_IMMEDIATE_MASK,
+ // but ld64 currently does this. This could be a potential bug, but
+ // for now, perform the same behavior to prevent mysterious bugs.
+ if ((p->opcode == BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB) &&
+ ((p->data / target->wordSize) < BIND_IMMEDIATE_MASK) &&
+ ((p->data % target->wordSize) == 0)) {
+ p->opcode = BIND_OPCODE_DO_BIND_ADD_ADDR_IMM_SCALED;
+ p->data /= target->wordSize;
+ }
+ }
}
static void flushOpcodes(const BindIR &op, raw_svector_ostream &os) {
@@ -383,6 +400,9 @@ static void flushOpcodes(const BindIR &op, raw_svector_ostream &os) {
encodeULEB128(op.consecutiveCount, os);
encodeULEB128(op.data, os);
break;
+ case BIND_OPCODE_DO_BIND_ADD_ADDR_IMM_SCALED:
+ os << static_cast<uint8_t>(op.opcode | op.data);
+ break;
default:
llvm_unreachable("cannot bind to an unrecognized symbol");
}
diff --git a/lld/test/MachO/bind-opcodes.s b/lld/test/MachO/bind-opcodes.s
index b313afbef8e6..0f8467ac5c49 100644
--- a/lld/test/MachO/bind-opcodes.s
+++ b/lld/test/MachO/bind-opcodes.s
@@ -1,15 +1,16 @@
-# REQUIRES: x86
+# REQUIRES: x86, arm
# RUN: rm -rf %t; split-file %s %t
# RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %t/foo.s -o %t/foo.o
-# RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %t/test.s -o %t/test.o
+# RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin --defsym PTR64=0 %t/test.s -o %t/test.o
# RUN: %lld -O2 -dylib %t/foo.o -o %t/libfoo.dylib
-# RUN: %lld -O2 -lSystem %t/test.o %t/libfoo.dylib -o %t/test
+# RUN: %lld -O2 -lSystem %t/test.o %t/libfoo.dylib -o %t/test-x86_64
-## Test:
+## Test (64-bit):
## 1/ We emit exactly one BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM per symbol.
## 2/ Combine BIND_OPCODE_DO_BIND and BIND_OPCODE_ADD_ADDR_ULEB pairs.
## 3/ Compact BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB
-# RUN: obj2yaml %t/test | FileCheck %s
+## 4/ Use BIND_OPCODE_DO_BIND_ADD_ADDR_IMM_SCALED if possible.
+# RUN: obj2yaml %t/test-x86_64 | FileCheck %s
# CHECK: BindOpcodes:
# CHECK-NEXT: Opcode: BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM
@@ -54,9 +55,8 @@
# CHECK-NEXT: Imm: 0
# CHECK-NEXT: ULEBExtraData: [ 0xFFFFFFFFFFFFEFD0 ]
# CHECK-NEXT: Symbol: ''
-# CHECK-NEXT: Opcode: BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB
-# CHECK-NEXT: Imm: 0
-# CHECK-NEXT: ULEBExtraData: [ 0x8 ]
+# CHECK-NEXT: Opcode: BIND_OPCODE_DO_BIND_ADD_ADDR_IMM_SCALED
+# CHECK-NEXT: Imm: 1
# CHECK-NEXT: Symbol: ''
# CHECK-NEXT: Opcode: BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB
# CHECK-NEXT: Imm: 0
@@ -69,16 +69,86 @@
# CHECK-NEXT: Imm: 0
# CHECK-NEXT: Symbol: ''
-# RUN: llvm-objdump --macho --bind %t/test | FileCheck %s --check-prefix=BIND
+# RUN: llvm-mc -filetype=obj -triple=arm64_32-apple-darwin %t/foo.s -o %t/foo.o
+# RUN: llvm-mc -filetype=obj -triple=arm64_32-apple-darwin --defsym PTR32=0 %t/test.s -o %t/test.o
+# RUN: %lld -arch arm64_32 -O2 -dylib %t/foo.o -o %t/libfoo.dylib
+# RUN: %lld -arch arm64_32 -O2 -dylib %t/test.o %t/libfoo.dylib -o %t/libtest-arm64_32.dylib
+
+## Test (32-bit):
+## 1/ We emit exactly one BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM per symbol.
+## 2/ Combine BIND_OPCODE_DO_BIND and BIND_OPCODE_ADD_ADDR_ULEB pairs.
+## 3/ Compact BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB
+## 4/ Use BIND_OPCODE_DO_BIND_ADD_ADDR_IMM_SCALED if possible.
+# RUN: obj2yaml %t/libtest-arm64_32.dylib | FileCheck %s --check-prefix=CHECK32
+
+# CHECK32: BindOpcodes:
+# CHECK32-NEXT: Opcode: BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM
+# CHECK32-NEXT: Imm: 0
+# CHECK32-NEXT: Symbol: _foo
+# CHECK32-NEXT: Opcode: BIND_OPCODE_SET_TYPE_IMM
+# CHECK32-NEXT: Imm: 1
+# CHECK32-NEXT: Symbol: ''
+# CHECK32-NEXT: Opcode: BIND_OPCODE_SET_DYLIB_ORDINAL_IMM
+# CHECK32-NEXT: Imm: 1
+# CHECK32-NEXT: Symbol: ''
+# CHECK32-NEXT: Opcode: BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB
+# CHECK32-NEXT: Imm: 1
+# CHECK32-NEXT: ULEBExtraData: [ 0x0 ]
+# CHECK32-NEXT: Symbol: ''
+# CHECK32-NEXT: Opcode: BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB
+# CHECK32-NEXT: Imm: 0
+# CHECK32-NEXT: ULEBExtraData: [ 0x2, 0x4 ]
+# CHECK32-NEXT: Symbol: ''
+# CHECK32-NEXT: Opcode: BIND_OPCODE_SET_ADDEND_SLEB
+# CHECK32-NEXT: Imm: 0
+# CHECK32-NEXT: SLEBExtraData: [ 1 ]
+# CHECK32-NEXT: Symbol: ''
+# CHECK32-NEXT: Opcode: BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB
+# CHECK32-NEXT: Imm: 0
+# CHECK32-NEXT: ULEBExtraData: [ 0x1004 ]
+# CHECK32-NEXT: Symbol: ''
+# CHECK32-NEXT: Opcode: BIND_OPCODE_SET_ADDEND_SLEB
+# CHECK32-NEXT: Imm: 0
+# CHECK32-NEXT: SLEBExtraData: [ 0 ]
+# CHECK32-NEXT: Symbol: ''
+# CHECK32-NEXT: Opcode: BIND_OPCODE_DO_BIND
+# CHECK32-NEXT: Imm: 0
+# CHECK32-NEXT: Symbol: ''
+# CHECK32-NEXT: Opcode: BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM
+# CHECK32-NEXT: Imm: 0
+# CHECK32-NEXT: Symbol: _bar
+# CHECK32-NEXT: Opcode: BIND_OPCODE_SET_TYPE_IMM
+# CHECK32-NEXT: Imm: 1
+# CHECK32-NEXT: Symbol: ''
+# CHECK32-NEXT: Opcode: BIND_OPCODE_ADD_ADDR_ULEB
+# CHECK32-NEXT: Imm: 0
+# CHECK32-NEXT: ULEBExtraData: [ 0xFFFFFFFFFFFFEFE8 ]
+# CHECK32-NEXT: Symbol: ''
+# CHECK32-NEXT: Opcode: BIND_OPCODE_DO_BIND_ADD_ADDR_IMM_SCALED
+# CHECK32-NEXT: Imm: 1
+# CHECK32-NEXT: Symbol: ''
+# CHECK32-NEXT: Opcode: BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB
+# CHECK32-NEXT: Imm: 0
+# CHECK32-NEXT: ULEBExtraData: [ 0x1004 ]
+# CHECK32-NEXT: Symbol: ''
+# CHECK32-NEXT: Opcode: BIND_OPCODE_DO_BIND
+# CHECK32-NEXT: Imm: 0
+# CHECK32-NEXT: Symbol: ''
+# CHECK32-NEXT: Opcode: BIND_OPCODE_DONE
+# CHECK32-NEXT: Imm: 0
+# CHECK32-NEXT: Symbol: ''
+
+# RUN: llvm-objdump --macho --bind %t/test-x86_64 | FileCheck %s -D#PTR=8 --check-prefix=BIND
+# RUN: llvm-objdump --macho --bind %t/libtest-arm64_32.dylib | FileCheck %s -D#PTR=4 --check-prefix=BIND
# BIND: Bind table:
-# BIND-NEXT: segment section address type addend dylib symbol
-# BIND-NEXT: __DATA __data 0x100001000 pointer 0 libfoo _foo
-# BIND-NEXT: __DATA __data 0x100001010 pointer 0 libfoo _foo
-# BIND-NEXT: __DATA __data 0x100001020 pointer 1 libfoo _foo
-# BIND-NEXT: __DATA __data 0x100002030 pointer 0 libfoo _foo
-# BIND-NEXT: __DATA __data 0x100001008 pointer 0 libfoo _bar
-# BIND-NEXT: __DATA __data 0x100001018 pointer 0 libfoo _bar
-# BIND-NEXT: __DATA __data 0x100002028 pointer 0 libfoo _bar
+# BIND-NEXT: segment section address type addend dylib symbol
+# BIND-NEXT: __DATA __data 0x[[#%X,DATA:]] pointer 0 libfoo _foo
+# BIND-NEXT: __DATA __data 0x[[#%.8X,DATA + mul(PTR, 2)]] pointer 0 libfoo _foo
+# BIND-NEXT: __DATA __data 0x[[#%.8X,DATA + mul(PTR, 4)]] pointer 1 libfoo _foo
+# BIND-NEXT: __DATA __data 0x[[#%.8X,DATA + 4096 + mul(PTR, 6)]] pointer 0 libfoo _foo
+# BIND-NEXT: __DATA __data 0x[[#%.8X,DATA + PTR]] pointer 0 libfoo _bar
+# BIND-NEXT: __DATA __data 0x[[#%.8X,DATA + mul(PTR, 3)]] pointer 0 libfoo _bar
+# BIND-NEXT: __DATA __data 0x[[#%.8X,DATA + 4096 + mul(PTR, 5)]] pointer 0 libfoo _bar
# BIND-EMPTY:
#--- foo.s
@@ -89,15 +159,27 @@ _bar:
.space 4
#--- test.s
+.ifdef PTR64
+.macro ptr val
+ .quad \val
+.endm
+.endif
+
+.ifdef PTR32
+.macro ptr val
+ .int \val
+.endm
+.endif
+
.data
-.quad _foo
-.quad _bar
-.quad _foo
-.quad _bar
-.quad _foo+1
+ptr _foo
+ptr _bar
+ptr _foo
+ptr _bar
+ptr _foo+1
.zero 0x1000
-.quad _bar
-.quad _foo
+ptr _bar
+ptr _foo
.globl _main
.text
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