[XCOFF] Display branch-absolute targets in hex. #72532

stephenpeckham · 2023-11-16T16:56:17Z

Branch-absolute instructions are currently printed in decimal, and negative addresses are printed as positive numbers.

With this change, addresses are printed in hex and negative addresses are converted to an unsigned 32- or 64-bit address.

llvmbot · 2023-11-16T16:56:47Z

@llvm/pr-subscribers-mc
@llvm/pr-subscribers-lld
@llvm/pr-subscribers-lld-elf

@llvm/pr-subscribers-llvm-binary-utilities

Author: None (stephenpeckham)

Changes

Branch-absolute instructions are currently printed in decimal, and negative addresses are printed as positive numbers.

With this change, addresses are printed in hex and negative addresses are converted to an unsigned 32- or 64-bit address.

Full diff: https://github.com/llvm/llvm-project/pull/72532.diff

5 Files Affected:

(modified) llvm/lib/Target/PowerPC/MCTargetDesc/PPCInstPrinter.cpp (+4-1)
(modified) llvm/lib/Target/PowerPC/PPCRegisterInfo.td (+3)
(added) llvm/test/tools/llvm-objdump/XCOFF/Inputs/abs32.o ()
(added) llvm/test/tools/llvm-objdump/XCOFF/Inputs/abs64.o ()
(added) llvm/test/tools/llvm-objdump/XCOFF/disassemble-abs.test (+37)

diff --git a/llvm/lib/Target/PowerPC/MCTargetDesc/PPCInstPrinter.cpp b/llvm/lib/Target/PowerPC/MCTargetDesc/PPCInstPrinter.cpp
index ccbb650c65365b4..f0a5cfcd5a78878 100644
--- a/llvm/lib/Target/PowerPC/MCTargetDesc/PPCInstPrinter.cpp
+++ b/llvm/lib/Target/PowerPC/MCTargetDesc/PPCInstPrinter.cpp
@@ -484,7 +484,10 @@ void PPCInstPrinter::printAbsBranchOperand(const MCInst *MI, unsigned OpNo,
   if (!MI->getOperand(OpNo).isImm())
     return printOperand(MI, OpNo, STI, O);
 
-  O << SignExtend32<32>((unsigned)MI->getOperand(OpNo).getImm() << 2);
+  uint64_t Imm = MI->getOperand(OpNo).getImm() << 2;
+  if (!TT.isPPC64())
+    Imm &= 0xffffffff;
+  O << formatHex(Imm);
 }
 
 void PPCInstPrinter::printcrbitm(const MCInst *MI, unsigned OpNo,
diff --git a/llvm/lib/Target/PowerPC/PPCRegisterInfo.td b/llvm/lib/Target/PowerPC/PPCRegisterInfo.td
index 6151faf403aaaf1..375e63654db1184 100644
--- a/llvm/lib/Target/PowerPC/PPCRegisterInfo.td
+++ b/llvm/lib/Target/PowerPC/PPCRegisterInfo.td
@@ -798,6 +798,7 @@ def directbrtarget : Operand<OtherVT> {
 def absdirectbrtarget : Operand<OtherVT> {
   let PrintMethod = "printAbsBranchOperand";
   let EncoderMethod = "getAbsDirectBrEncoding";
+  let DecoderMethod = "decodeDirectBrTarget";
   let ParserMatchClass = PPCDirectBrAsmOperand;
 }
 def PPCCondBrAsmOperand : AsmOperandClass {
@@ -814,6 +815,7 @@ def condbrtarget : Operand<OtherVT> {
 def abscondbrtarget : Operand<OtherVT> {
   let PrintMethod = "printAbsBranchOperand";
   let EncoderMethod = "getAbsCondBrEncoding";
+  let DecoderMethod = "decodeCondBrTarget";
   let ParserMatchClass = PPCCondBrAsmOperand;
 }
 def calltarget : Operand<iPTR> {
@@ -826,6 +828,7 @@ def calltarget : Operand<iPTR> {
 def abscalltarget : Operand<iPTR> {
   let PrintMethod = "printAbsBranchOperand";
   let EncoderMethod = "getAbsDirectBrEncoding";
+  let DecoderMethod = "decodeDirectBrTarget";
   let ParserMatchClass = PPCDirectBrAsmOperand;
 }
 def PPCCRBitMaskOperand : AsmOperandClass {
diff --git a/llvm/test/tools/llvm-objdump/XCOFF/Inputs/abs32.o b/llvm/test/tools/llvm-objdump/XCOFF/Inputs/abs32.o
new file mode 100644
index 000000000000000..eda8e461736e033
Binary files /dev/null and b/llvm/test/tools/llvm-objdump/XCOFF/Inputs/abs32.o differ
diff --git a/llvm/test/tools/llvm-objdump/XCOFF/Inputs/abs64.o b/llvm/test/tools/llvm-objdump/XCOFF/Inputs/abs64.o
new file mode 100644
index 000000000000000..ae9e0e87d001730
Binary files /dev/null and b/llvm/test/tools/llvm-objdump/XCOFF/Inputs/abs64.o differ
diff --git a/llvm/test/tools/llvm-objdump/XCOFF/disassemble-abs.test b/llvm/test/tools/llvm-objdump/XCOFF/disassemble-abs.test
new file mode 100644
index 000000000000000..dc83b3540ca0a76
--- /dev/null
+++ b/llvm/test/tools/llvm-objdump/XCOFF/disassemble-abs.test
@@ -0,0 +1,37 @@
+# RUN: llvm-objdump -d %p/Inputs/abs32.o | \
+# RUN:   FileCheck %s
+
+# RUN: llvm-objdump -d %p/Inputs/abs64.o | \
+# RUN:   FileCheck --check-prefixes=CHECK64 %s
+
+## Object files assembled on AIX from the following source:
+##        .csect [PR]
+##.main:
+##        .globl .main
+##        .extern .function
+##        bla     .function
+##        btla    .function
+##        ba      0x1234
+##        ba      -32
+##        bta     0x2348
+##        bta     -256
+
+CHECK:        Inputs/abs32.o:	file format aixcoff-rs6000
+CHECK:        Disassembly of section .text:
+CHECK:        00000000 <.main>:
+CHECK:            0: 48 00 00 03   bla 0x0
+CHECK-NEXT:       4: 41 80 00 03   btla    0, 0x0
+CHECK-NEXT:       8: 48 00 12 36   ba 0x1234
+CHECK-NEXT:       c: 4b ff ff e2   ba 0xffffffe0
+CHECK-NEXT:      10: 41 80 23 4a   bta     0, 0x2348
+CHECK-NEXT:      14: 41 80 ff 02   bta     0, 0xffffff00
+
+CHECK64:      Inputs/abs64.o: file format aix5coff64-rs6000
+CHECK64:      Disassembly of section .text:
+CHECK64:      0000000000000000 <.main>:
+CHECK64-NEXT:       0: 48 00 00 03   bla 0x0
+CHECK64-NEXT:       4: 41 80 00 03   btla    0, 0x0
+CHECK64-NEXT:       8: 48 00 12 36   ba 0x1234
+CHECK64-NEXT:       c: 4b ff ff e2   ba 0xffffffffffffffe0
+CHECK64-NEXT:      10: 41 80 23 4a   bta     0, 0x2348
+CHECK64-NEXT:      14: 41 80 ff 02   bta     0, 0xffffffffffffff00

github-actions · 2023-11-22T19:53:42Z

✅ With the latest revision this PR passed the Python code formatter.

github-actions · 2023-11-22T19:54:25Z

✅ With the latest revision this PR passed the C/C++ code formatter.

chenzheng1030 · 2023-12-05T06:43:48Z

llvm/test/tools/llvm-objdump/XCOFF/disassemble-abs.test

@@ -0,0 +1,37 @@
+# RUN: llvm-objdump -d %p/Inputs/abs32.o | \


We can use yaml2obj to generate the object? Raw object input should always be avoided.

obj2yaml abs32.o -o m.yaml yaml2obj m.yaml -o t.o $llvm-objdump -d t.o t.o: file format aixcoff-rs6000 Disassembly of section .text: 00000000 <.main>: 0: 48 00 00 03 bla 0 4: 41 80 00 03 btla 0, 0 8: 48 00 12 36 ba 4660 c: 4b ff ff e2 ba 67108832 10: 41 80 23 4a bta 0, 9032 14: 41 80 ff 02 bta 0, 65280

Thanks for the suggestion. It looks like obj2yaml has some bugs. The generated object files are not valid (I cannot run ld -r t.o). For the 64-bit testcase, llvm-objdump fails. I'll see what I can do.

Is it necessary to generate an object that can pass ld -r for this patch? I assume we only need to correctly dump the assembly code?

Below yaml for XCOFF64 can get an object which can be disassembled by llvm-objdump.

--- !XCOFF FileHeader: MagicNumber: 0x1F7 NumberOfSections: 1 CreationTime: 1701859282 AuxiliaryHeaderSize: 0 Flags: 0x0 Sections: - Name: .text Address: 0x0 Size: 0x18 FileOffsetToData: 0x60 FileOffsetToRelocations: 0x78 FileOffsetToLineNumbers: 0x0 NumberOfRelocations: 0x2 NumberOfLineNumbers: 0x0 Flags: [ STYP_TEXT ] SectionData: 4800000341800003480012364BFFFFE24180234A4180FF02 Relocations: - Address: 0x0 Symbol: 0x1 Info: 0x99 Type: 0x18 - Address: 0x6 Symbol: 0x1 Info: 0x8F Type: 0x18 Symbols: - Name: .file Section: N_DEBUG StorageClass: C_FILE NumberOfAuxEntries: 0 - Name: .function Section: N_UNDEF StorageClass: C_EXT NumberOfAuxEntries: 1 AuxEntries: - Type: AUX_CSECT StorageMappingClass: XMC_PR SymbolAlignmentAndType: 0 - Name: '' Section: .text StorageClass: C_HIDEXT NumberOfAuxEntries: 1 AuxEntries: - Type: AUX_CSECT StorageMappingClass: XMC_PR SymbolAlignmentAndType: 1 - Name: .main Section: .text StorageClass: C_EXT NumberOfAuxEntries: 1 AuxEntries: - Type: AUX_CSECT StorageMappingClass: XMC_PR SymbolAlignmentAndType: 2 StringTable: Strings: - .file - .function - .text - .main

and below yaml is for XCOFF32:

--- !XCOFF FileHeader: MagicNumber: 0x1DF NumberOfSections: 1 CreationTime: 1701859282 AuxiliaryHeaderSize: 0 Flags: 0x0 Sections: - Name: .text Address: 0x0 Size: 0x18 FileOffsetToData: 0x3C FileOffsetToRelocations: 0x54 FileOffsetToLineNumbers: 0x0 NumberOfRelocations: 0x2 NumberOfLineNumbers: 0x0 Flags: [ STYP_TEXT ] SectionData: 4800000341800003480012364BFFFFE24180234A4180FF02 Relocations: - Address: 0x0 Symbol: 0x4 Info: 0x99 Type: 0x18 - Address: 0x6 Symbol: 0x4 Info: 0x8F Type: 0x18 Symbols: - Name: '' Section: .text StorageClass: C_HIDEXT NumberOfAuxEntries: 1 AuxEntries: - Type: AUX_CSECT StorageMappingClass: XMC_PR SymbolAlignmentAndType: 1 - Name: .main Section: .text StorageClass: C_EXT NumberOfAuxEntries: 1 AuxEntries: - Type: AUX_CSECT StorageMappingClass: XMC_PR SymbolAlignmentAndType: 2 - Name: .function Section: N_UNDEF StorageClass: C_EXT NumberOfAuxEntries: 1 AuxEntries: - Type: AUX_CSECT StorageMappingClass: XMC_PR SymbolAlignmentAndType: 0

stephenpeckham · 2023-12-06T19:36:54Z

Thanks for your help @chenzheng1030. I have deleted the object files and I'm using yaml2obj.

chenzheng1030

LGTM. Thanks for making this improvement.

chenzheng1030 · 2023-12-07T02:23:49Z

llvm/lib/Target/PowerPC/PPCRegisterInfo.td

@@ -798,6 +798,7 @@ def directbrtarget : Operand<OtherVT> {
 def absdirectbrtarget : Operand<OtherVT> {
  let PrintMethod = "printAbsBranchOperand";
  let EncoderMethod = "getAbsDirectBrEncoding";
+  let DecoderMethod = "decodeDirectBrTarget";


This seems like a bug related to branch instruction decode?
Normally we need another patch to fix this as the fix here is not same with this patch's purpose.
Since this change is quite small, let's put them together.

stephenpeckham added the tools:llvm-objdump label Nov 16, 2023

stephenpeckham requested review from diggerlin and jh7370 November 16, 2023 16:56

stephenpeckham self-assigned this Nov 16, 2023

llvmbot added the llvm:binary-utilities label Nov 16, 2023

stephenpeckham requested review from antiagainst, kuhar, JDevlieghere, nikic and a team as code owners November 22, 2023 19:51

stephenpeckham closed this Nov 22, 2023

stephenpeckham force-pushed the peckham/absbranch branch from 9f2e37e to 6f0c52e Compare November 22, 2023 20:02

stephenpeckham added 2 commits November 22, 2023 15:23

Display branch-absolute targets in hex.

eefa464

Fix ELF testcase

0af8513

stephenpeckham reopened this Nov 22, 2023

llvmbot added lld lld:ELF labels Nov 22, 2023

Fix additional ELF tests

93096eb

llvmbot added the mc Machine (object) code label Nov 22, 2023

Updated test

6fdbc8f

ldionne removed request for a team November 22, 2023 23:32

nikic removed their request for review November 24, 2023 09:47

antiagainst removed their request for review November 27, 2023 04:25

stephenpeckham added 2 commits November 28, 2023 16:07

Update branch-absolute tests

d59c994

Use cast to convert to 32-bit value

3294c7d

diggerlin requested a review from chenzheng1030 December 4, 2023 16:33

chenzheng1030 reviewed Dec 5, 2023

View reviewed changes

Use yaml2obj instead of raw object files

e443364

Update testcase to use yaml2obj

76aab8a

chenzheng1030 approved these changes Dec 7, 2023

View reviewed changes

stephenpeckham merged commit 2fd7657 into llvm:main Dec 13, 2023
4 checks passed

vitalybuka added a commit that referenced this pull request Dec 14, 2023

[XCOFF] Fix UB 'left shift of negative value' after #72532

36477f7

chenzheng1030 mentioned this pull request Jan 10, 2024

UB in XCOFF after #72532 #75520

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[XCOFF] Display branch-absolute targets in hex. #72532

[XCOFF] Display branch-absolute targets in hex. #72532

stephenpeckham commented Nov 16, 2023

llvmbot commented Nov 16, 2023 •

edited

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edited

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edited

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chenzheng1030 Dec 7, 2023

		@@ -0,0 +1,37 @@
		# RUN: llvm-objdump -d %p/Inputs/abs32.o \| \

[XCOFF] Display branch-absolute targets in hex. #72532

[XCOFF] Display branch-absolute targets in hex. #72532

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