Register assembly printer passes #138348

MatzeB · 2025-05-02T21:16:40Z

Register assembly printer passes in the pass registry.

This makes it possible to use llc -start-before=<target>-asm-printer ... in tests.

Adds a char &ID parameter to the AssemblyPrinter constructor to allow targets to use the INITIALIZE_PASS macros and register the pass in the pass registry. This currently has a default parameter so it won't break any targets that have not been updated.

github-actions · 2025-05-02T21:18:57Z

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

MatzeB · 2025-05-02T21:21:33Z

This currently changes AArch64 and X86 to register their AsmPrinter passes and adjusts some tests that seem like they just wanted to run assembly printing.

Putting this up for comments/feedback before I do all the typing for the other 23 targets... Or would be acceptable to land this with just some targets adapted?

llvmbot · 2025-05-02T21:25:31Z

@llvm/pr-subscribers-backend-spir-v
@llvm/pr-subscribers-backend-msp430
@llvm/pr-subscribers-backend-m68k
@llvm/pr-subscribers-backend-risc-v
@llvm/pr-subscribers-backend-webassembly
@llvm/pr-subscribers-backend-aarch64
@llvm/pr-subscribers-debuginfo

@llvm/pr-subscribers-backend-x86

Author: Matthias Braun (MatzeB)

Changes

Register assembly printer passes in the pass registry.

This makes it possible to use llc -start-before=<target>-asm-printer ... in tests.

Adds a char &ID parameter to the AssemblyPrinter constructor to allow targets to use the INITIALIZE_PASS macros and register the pass in the pass registry. This currently has a default parameter so it won't break any targets that have not been updated.

Full diff: https://github.com/llvm/llvm-project/pull/138348.diff

14 Files Affected:

(modified) llvm/include/llvm/CodeGen/AsmPrinter.h (+2-1)
(modified) llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp (+2-1)
(modified) llvm/lib/Target/AArch64/AArch64.h (+1)
(modified) llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp (+9-2)
(modified) llvm/lib/Target/AArch64/AArch64TargetMachine.cpp (+1)
(modified) llvm/lib/Target/X86/X86.h (+1)
(modified) llvm/lib/Target/X86/X86AsmPrinter.cpp (+7-1)
(modified) llvm/lib/Target/X86/X86AsmPrinter.h (+4)
(modified) llvm/lib/Target/X86/X86TargetMachine.cpp (+1)
(modified) llvm/test/CodeGen/X86/align-basic-block-sections.mir (+1-1)
(modified) llvm/test/CodeGen/X86/basic-block-address-map-mir-parse.mir (+1-1)
(modified) llvm/test/CodeGen/X86/basic-block-sections-mir-parse.mir (+1-1)
(modified) llvm/test/DebugInfo/MIR/AArch64/clobber-sp.mir (+1-1)
(modified) llvm/test/DebugInfo/X86/single-location.mir (+1-1)

diff --git a/llvm/include/llvm/CodeGen/AsmPrinter.h b/llvm/include/llvm/CodeGen/AsmPrinter.h
index 79d23986f3b43..9132a0a6ea5a3 100644
--- a/llvm/include/llvm/CodeGen/AsmPrinter.h
+++ b/llvm/include/llvm/CodeGen/AsmPrinter.h
@@ -240,7 +240,8 @@ class AsmPrinter : public MachineFunctionPass {
   bool DbgInfoAvailable = false;
 
 protected:
-  explicit AsmPrinter(TargetMachine &TM, std::unique_ptr<MCStreamer> Streamer);
+  AsmPrinter(TargetMachine &TM, std::unique_ptr<MCStreamer> Streamer,
+             char &ID = AsmPrinter::ID);
 
 public:
   ~AsmPrinter() override;
diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index bdcd54a135da9..d7710212e8cc3 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -382,7 +382,8 @@ Align AsmPrinter::getGVAlignment(const GlobalObject *GV, const DataLayout &DL,
   return Alignment;
 }
 
-AsmPrinter::AsmPrinter(TargetMachine &tm, std::unique_ptr<MCStreamer> Streamer)
+AsmPrinter::AsmPrinter(TargetMachine &tm, std::unique_ptr<MCStreamer> Streamer,
+                       char &ID)
     : MachineFunctionPass(ID), TM(tm), MAI(tm.getMCAsmInfo()),
       OutContext(Streamer->getContext()), OutStreamer(std::move(Streamer)),
       SM(*this) {
diff --git a/llvm/lib/Target/AArch64/AArch64.h b/llvm/lib/Target/AArch64/AArch64.h
index ffa578d412b3c..a5bb7520aec0d 100644
--- a/llvm/lib/Target/AArch64/AArch64.h
+++ b/llvm/lib/Target/AArch64/AArch64.h
@@ -77,6 +77,7 @@ ModulePass *createAArch64Arm64ECCallLoweringPass();
 void initializeAArch64A53Fix835769Pass(PassRegistry&);
 void initializeAArch64A57FPLoadBalancingPass(PassRegistry&);
 void initializeAArch64AdvSIMDScalarPass(PassRegistry&);
+void initializeAArch64AsmPrinterPass(PassRegistry&);
 void initializeAArch64PointerAuthPass(PassRegistry&);
 void initializeAArch64BranchTargetsPass(PassRegistry&);
 void initializeAArch64CFIFixupPass(PassRegistry&);
diff --git a/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp b/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
index 870df4c387ca4..38be677ec805b 100644
--- a/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
+++ b/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
@@ -96,9 +96,11 @@ class AArch64AsmPrinter : public AsmPrinter {
       SectionToImportedFunctionCalls;
 
 public:
+  static char ID;
+
   AArch64AsmPrinter(TargetMachine &TM, std::unique_ptr<MCStreamer> Streamer)
-      : AsmPrinter(TM, std::move(Streamer)), MCInstLowering(OutContext, *this),
-        FM(*this) {}
+      : AsmPrinter(TM, std::move(Streamer), ID),
+        MCInstLowering(OutContext, *this), FM(*this) {}
 
   StringRef getPassName() const override { return "AArch64 Assembly Printer"; }
 
@@ -3523,6 +3525,11 @@ const MCExpr *AArch64AsmPrinter::lowerConstant(const Constant *CV,
   return AsmPrinter::lowerConstant(CV, BaseCV, Offset);
 }
 
+char AArch64AsmPrinter::ID = 0;
+
+INITIALIZE_PASS(AArch64AsmPrinter, "aarch64-asm-printer",
+                "AArch64 Assmebly Printer", false, false)
+
 // Force static initialization.
 extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeAArch64AsmPrinter() {
   RegisterAsmPrinter<AArch64AsmPrinter> X(getTheAArch64leTarget());
diff --git a/llvm/lib/Target/AArch64/AArch64TargetMachine.cpp b/llvm/lib/Target/AArch64/AArch64TargetMachine.cpp
index 431076f188d98..5693a551e679f 100644
--- a/llvm/lib/Target/AArch64/AArch64TargetMachine.cpp
+++ b/llvm/lib/Target/AArch64/AArch64TargetMachine.cpp
@@ -235,6 +235,7 @@ extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeAArch64Target() {
   initializeAArch64A53Fix835769Pass(PR);
   initializeAArch64A57FPLoadBalancingPass(PR);
   initializeAArch64AdvSIMDScalarPass(PR);
+  initializeAArch64AsmPrinterPass(PR);
   initializeAArch64BranchTargetsPass(PR);
   initializeAArch64CollectLOHPass(PR);
   initializeAArch64CompressJumpTablesPass(PR);
diff --git a/llvm/lib/Target/X86/X86.h b/llvm/lib/Target/X86/X86.h
index e6c0612101bc7..ba53ffd857fb3 100644
--- a/llvm/lib/Target/X86/X86.h
+++ b/llvm/lib/Target/X86/X86.h
@@ -176,6 +176,7 @@ void initializeFPSPass(PassRegistry &);
 void initializeFixupBWInstPassPass(PassRegistry &);
 void initializeFixupLEAPassPass(PassRegistry &);
 void initializeX86ArgumentStackSlotPassPass(PassRegistry &);
+void initializeX86AsmPrinterPass(PassRegistry &);
 void initializeX86FixupInstTuningPassPass(PassRegistry &);
 void initializeX86FixupVectorConstantsPassPass(PassRegistry &);
 void initializeWinEHStatePassPass(PassRegistry &);
diff --git a/llvm/lib/Target/X86/X86AsmPrinter.cpp b/llvm/lib/Target/X86/X86AsmPrinter.cpp
index 29ec14e8cf46d..5f5bfc70e8a1a 100644
--- a/llvm/lib/Target/X86/X86AsmPrinter.cpp
+++ b/llvm/lib/Target/X86/X86AsmPrinter.cpp
@@ -17,6 +17,7 @@
 #include "MCTargetDesc/X86MCTargetDesc.h"
 #include "MCTargetDesc/X86TargetStreamer.h"
 #include "TargetInfo/X86TargetInfo.h"
+#include "X86.h"
 #include "X86InstrInfo.h"
 #include "X86MachineFunctionInfo.h"
 #include "X86Subtarget.h"
@@ -53,7 +54,7 @@ using namespace llvm;
 
 X86AsmPrinter::X86AsmPrinter(TargetMachine &TM,
                              std::unique_ptr<MCStreamer> Streamer)
-    : AsmPrinter(TM, std::move(Streamer)), FM(*this) {}
+    : AsmPrinter(TM, std::move(Streamer), ID), FM(*this) {}
 
 //===----------------------------------------------------------------------===//
 // Primitive Helper Functions.
@@ -1086,6 +1087,11 @@ void X86AsmPrinter::emitEndOfAsmFile(Module &M) {
   }
 }
 
+char X86AsmPrinter::ID = 0;
+
+INITIALIZE_PASS(X86AsmPrinter, "x86-asm-printer", "X86 Assembly Printer", false,
+                false)
+
 //===----------------------------------------------------------------------===//
 // Target Registry Stuff
 //===----------------------------------------------------------------------===//
diff --git a/llvm/lib/Target/X86/X86AsmPrinter.h b/llvm/lib/Target/X86/X86AsmPrinter.h
index 8dd7fa4431680..61d8f45501ab1 100644
--- a/llvm/lib/Target/X86/X86AsmPrinter.h
+++ b/llvm/lib/Target/X86/X86AsmPrinter.h
@@ -25,6 +25,10 @@ class X86Subtarget;
 class TargetMachine;
 
 class LLVM_LIBRARY_VISIBILITY X86AsmPrinter : public AsmPrinter {
+public:
+  static char ID;
+
+private:
   const X86Subtarget *Subtarget = nullptr;
   FaultMaps FM;
   std::unique_ptr<MCCodeEmitter> CodeEmitter;
diff --git a/llvm/lib/Target/X86/X86TargetMachine.cpp b/llvm/lib/Target/X86/X86TargetMachine.cpp
index 975b94c18fb7f..5fff9c30205dd 100644
--- a/llvm/lib/Target/X86/X86TargetMachine.cpp
+++ b/llvm/lib/Target/X86/X86TargetMachine.cpp
@@ -102,6 +102,7 @@ extern "C" LLVM_C_ABI void LLVMInitializeX86Target() {
   initializeX86ReturnThunksPass(PR);
   initializeX86DAGToDAGISelLegacyPass(PR);
   initializeX86ArgumentStackSlotPassPass(PR);
+  initializeX86AsmPrinterPass(PR);
   initializeX86FixupInstTuningPassPass(PR);
   initializeX86FixupVectorConstantsPassPass(PR);
   initializeX86DynAllocaExpanderPass(PR);
diff --git a/llvm/test/CodeGen/X86/align-basic-block-sections.mir b/llvm/test/CodeGen/X86/align-basic-block-sections.mir
index 17a675f5c5b72..02ccbcf0c0897 100644
--- a/llvm/test/CodeGen/X86/align-basic-block-sections.mir
+++ b/llvm/test/CodeGen/X86/align-basic-block-sections.mir
@@ -1,5 +1,5 @@
 # Check if the alignment directive is put on the correct place when the basic block section option is used.
-# RUN: llc -mtriple x86_64-unknown-linux-gnu -start-after=bbsections-prepare  %s -o - | FileCheck %s -check-prefix=CHECK
+# RUN: llc -mtriple x86_64-unknown-linux-gnu -start-before=x86-asm-printer %s -o - | FileCheck %s -check-prefix=CHECK
 
 # How to generate the input:
 # foo.c
diff --git a/llvm/test/CodeGen/X86/basic-block-address-map-mir-parse.mir b/llvm/test/CodeGen/X86/basic-block-address-map-mir-parse.mir
index 8ac93c79fa5a2..a49a4e2726021 100644
--- a/llvm/test/CodeGen/X86/basic-block-address-map-mir-parse.mir
+++ b/llvm/test/CodeGen/X86/basic-block-address-map-mir-parse.mir
@@ -1,5 +1,5 @@
 # Start after bbsections0-prepare and check that the BB address map is generated.
-# RUN: llc -mtriple x86_64-unknown-linux-gnu -start-after=bbsections-prepare -basic-block-address-map %s -o - | FileCheck %s -check-prefix=CHECK
+# RUN: llc -mtriple x86_64-unknown-linux-gnu -start-before=x86-asm-printer -basic-block-address-map %s -o - | FileCheck %s -check-prefix=CHECK
 
 # How to generate the input:
 # foo.cc
diff --git a/llvm/test/CodeGen/X86/basic-block-sections-mir-parse.mir b/llvm/test/CodeGen/X86/basic-block-sections-mir-parse.mir
index 967622a11cd2b..e49ff140935a3 100644
--- a/llvm/test/CodeGen/X86/basic-block-sections-mir-parse.mir
+++ b/llvm/test/CodeGen/X86/basic-block-sections-mir-parse.mir
@@ -1,5 +1,5 @@
 # Start after bbsections0-prepare and check if the right code is generated.
-# RUN: llc -mtriple x86_64-unknown-linux-gnu -start-after=bbsections-prepare  %s -o - | FileCheck %s -check-prefix=CHECK
+# RUN: llc -mtriple x86_64-unknown-linux-gnu -start-before=x86-asm-printer  %s -o - | FileCheck %s -check-prefix=CHECK
 
 
 # How to generate the input:
diff --git a/llvm/test/DebugInfo/MIR/AArch64/clobber-sp.mir b/llvm/test/DebugInfo/MIR/AArch64/clobber-sp.mir
index c245684f1fca8..b248ee76a4141 100644
--- a/llvm/test/DebugInfo/MIR/AArch64/clobber-sp.mir
+++ b/llvm/test/DebugInfo/MIR/AArch64/clobber-sp.mir
@@ -1,4 +1,4 @@
-# RUN: llc -start-after=livedebugvalues -filetype=obj -o - %s \
+# RUN: llc -start-before=aarch64-asm-printer -filetype=obj -o - %s \
 # RUN:   | llvm-dwarfdump - | FileCheck %s
 # CHECK: .debug_info contents:
 # CHECK: DW_TAG_formal_parameter
diff --git a/llvm/test/DebugInfo/X86/single-location.mir b/llvm/test/DebugInfo/X86/single-location.mir
index 79049e31f3710..a1a167eda628b 100644
--- a/llvm/test/DebugInfo/X86/single-location.mir
+++ b/llvm/test/DebugInfo/X86/single-location.mir
@@ -1,4 +1,4 @@
-# RUN: llc -start-after=livedebugvalues --filetype=obj %s -o - \
+# RUN: llc -start-before=x86-asm-printer --filetype=obj %s -o - \
 # RUN:     | llvm-dwarfdump -v - | FileCheck %s
 #
 # Generated at -O2, stopped after livedebugvalues, with some metadata removed

lenary · 2025-05-03T06:33:31Z

Or would be acceptable to land this with just some targets adapted?

I think it would be acceptable. RISC-V lgtm.

MatzeB · 2025-05-07T00:13:02Z

I believe SPIRV failures are pre-existing, and SPIRV is an experimental target.

Register assembly printer passes in the pass registry. This makes it possible to use `llc -start-before=<target>-asm-printer ...` in tests. Adds a `char &ID` parameter to the AssemblyPrinter constructor to allow targets to use the `INITIALIZE_PASS` macros and register the pass in the pass registry. This currently has a default parameter so it won't break any targets that have not been updated.

optimisan · 2025-05-15T10:16:50Z

llvm/lib/Target/AMDGPU/AMDGPUAsmPrinter.cpp

@@ -1742,3 +1742,8 @@ void AMDGPUAsmPrinter::emitResourceUsageRemarks(
    EmitResourceUsageRemark("BytesLDS", "LDS Size [bytes/block]",
                            CurrentProgramInfo.LDSSize);
 }
+
+char AMDGPUAsmPrinter::ID = 0;


Missing the corresponding argument in the constructor

optimisan · 2025-05-15T10:30:25Z

llvm/test/CodeGen/RISCV/instruction-count-remark.mir

@@ -1,4 +1,4 @@
-# RUN: llc -mtriple=riscv32 -verify-machineinstrs -start-before=riscv-expand-pseudo -simplify-mir -o /dev/null -pass-remarks-analysis=asm-printer %s 2>&1 | FileCheck %s
+# RUN: llc -mtriple=riscv32 -verify-machineinstrs -start-before=riscv-asm-printer -simplify-mir -o /dev/null -pass-remarks-analysis=asm-printer %s 2>&1 | FileCheck %s


Since this was passing I didn't review too closely, but all of these tests are passing for the wrong reasons:

TargetPassConfig does not handle the AsmPrinter; it is directly added to the pipeline outside of TargetPassConfig. Rather, what it does handle is determining if the pass pipeline runs till the AsmPrinter (which is incorrectly named willCompleteCodeGenPipeline). Based on this, either AsmPrinter or MIRPrinter pass is added at the end.

Problem is TargetPassConfig does not check if the provided passes in these pipeline-slicing options actually are in the pipeline -- if they match we slice, else we do nothing.

So here we can substitute riscv-asm-printer with any pass that is not in the pipeline (try something like irtranslator or x86-asm-printer)

Further, this test fails on qualifying this (without changing the pipeline) with -stop-after=riscv-asm-printer (why? Because willCompleteCodegenPipeline does not properly check if indeed said pass was in the pipeline)

All in all -stop-before=xx-asm-printer and -start-before=xx-asm-printer work as intended, but -stop-after and -start-after do not (they do the same thing as their "before" counterparts)

I'm not sure if we should try to fix this; this issue is already fixed in the NPM path and no tests reference asm-printer like this.

Register assembly printer passes

e288df6

MatzeB requested review from efriedma-quic, davemgreen, arsenm, cdevadas and optimisan May 2, 2025 21:21

MatzeB marked this pull request as ready for review May 2, 2025 21:25

llvmbot added backend:AArch64 backend:X86 debuginfo labels May 2, 2025

llvmbot added backend:AMDGPU backend:RISC-V backend:WebAssembly labels May 2, 2025

Add some more tests and targets

aa52b73

MatzeB force-pushed the register-asm-printer branch from a86d5b9 to aa52b73 Compare May 2, 2025 22:11

arsenm approved these changes May 3, 2025

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optimisan approved these changes May 3, 2025

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Change remaining targets

2df45ce

llvmbot added backend:ARM backend:Hexagon backend:MSP430 backend:PowerPC backend:Sparc backend:SystemZ backend:m68k backend:SPIR-V labels May 5, 2025

llvmbot added backend:NVPTX backend:loongarch backend:Xtensa labels May 5, 2025

MatzeB mentioned this pull request May 6, 2025

Unrelated CI failure: "'OMP.inc' has been modified since the precompiled header was built" #138719

Closed

MatzeB added 2 commits May 6, 2025 09:47

Merge remote-tracking branch 'github/main' into register-asm-printer

f86e7ac

Fix formatting

0affae1

MatzeB merged commit 675cb70 into llvm:main May 7, 2025
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		@@ -1,4 +1,4 @@
		# RUN: llc -mtriple=riscv32 -verify-machineinstrs -start-before=riscv-expand-pseudo -simplify-mir -o /dev/null -pass-remarks-analysis=asm-printer %s 2>&1 \| FileCheck %s
		# RUN: llc -mtriple=riscv32 -verify-machineinstrs -start-before=riscv-asm-printer -simplify-mir -o /dev/null -pass-remarks-analysis=asm-printer %s 2>&1 \| FileCheck %s

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