[llvm-commits] [llvm] r131705 - /llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp

[Jakob Stoklund Olesen]

On May 19, 2011, at 7:38 PM, Cameron Zwarich wrote:

> On May 19, 2011, at 5:46 PM, Jakob Stoklund Olesen wrote:
> 
>> On May 19, 2011, at 4:44 PM, Cameron Zwarich wrote:
>> 
>>> Author: zwarich
>>> Date: Thu May 19 18:44:34 2011
>>> New Revision: 131705
>>> 
>>> URL: http://llvm.org/viewvc/llvm-project?rev=131705&view=rev
>>> Log:
>>> Fix PR9955 by only attaching load memory operands to load instructions and
>>> similarly for stores. Now "make check" passes with the MachineVerifier forced
>>> on with the VerifyCoalescing option!
>> 
>> Woot!
>> 
>> Do you know how slow the verifier is compared to, say, register coalescing? It may be worthwhile to run at least one pass in +Asserts builds.
> 
> I haven't run any timings, partially since it doesn't run as a separate pass with VerifyCoalescing (we should probably change that). It's not yet ready to be turned on in +Asserts builds, since it has some failures on test-suite. Once it passes test-suite on x86 and ARM and survives a self-host, we should consider turning it on for +Asserts builds. We should also turn it on for all "make check" tests somehow.

This still finds a number of issues:

diff --git a/lib/CodeGen/LLVMTargetMachine.cpp b/lib/CodeGen/LLVMTargetMachine.cpp
index 13cd45e..4049599 100644
--- a/lib/CodeGen/LLVMTargetMachine.cpp
+++ b/lib/CodeGen/LLVMTargetMachine.cpp
@@ -417,6 +417,10 @@ bool LLVMTargetMachine::addCommonCodeGenPasses(PassManagerBase &PM,
   if (addPreRegAlloc(PM, OptLevel))
     printAndVerify(PM, "After PreRegAlloc passes");
 
+#ifndef NDEBUG
+  PM.add(createMachineVerifierPass("Before register allocation"));
+#endif
+
   // Perform register allocation.
   PM.add(createRegisterAllocator(OptLevel));
   printAndVerify(PM, "After Register Allocation");

Failing Tests (20):
    Clang :: CodeGenCXX/array-construction.cpp
    Clang :: CodeGenCXX/constructor-for-array-members.cpp
    Clang :: CodeGenCXX/ptr-to-member-function.cpp
    Clang :: CodeGenObjC/debug-info-getter-name.m
    Clang :: CodeGenObjC/instance-method-metadata.m
    LLVM :: CodeGen/ARM/2010-08-04-StackVariable.ll
    LLVM :: CodeGen/ARM/fast-isel-crash.ll
    LLVM :: CodeGen/ARM/fast-isel-static.ll
    LLVM :: CodeGen/ARM/fast-isel.ll
    LLVM :: CodeGen/PowerPC/2008-02-05-LiveIntervalsAssert.ll
    LLVM :: CodeGen/PowerPC/2008-06-23-LiveVariablesCrash.ll
    LLVM :: CodeGen/PowerPC/indirectbr.ll
    LLVM :: CodeGen/Thumb2/2010-02-24-BigStack.ll
    LLVM :: CodeGen/X86/2009-08-23-SubRegReuseUndo.ll
    LLVM :: CodeGen/X86/MachineSink-CritEdge.ll
    LLVM :: CodeGen/X86/fast-isel-atomic.ll
    LLVM :: CodeGen/X86/fast-isel-gep.ll
    LLVM :: CodeGen/X86/fast-isel-x86-64.ll
    LLVM :: CodeGen/X86/fold-mul-lohi.ll
    LLVM :: CodeGen/X86/sext-subreg.ll

Running just one pass of verification is a bit slow, though:

   ---User Time---   --System Time--   --User+System--   ---Wall Time---  --- Name ---
  163.6872 ( 84.1%)   2.6591 ( 57.1%)  166.3463 ( 83.4%)  166.3893 ( 83.4%)  Verify generated machine code
  15.0122 (  7.7%)   1.3569 ( 29.1%)  16.3691 (  8.2%)  16.3692 (  8.2%)  X86 DAG->DAG Instruction Selection
   2.5570 (  1.3%)   0.0163 (  0.4%)   2.5733 (  1.3%)   2.5729 (  1.3%)  Live Variable Analysis
   2.4707 (  1.3%)   0.0117 (  0.3%)   2.4824 (  1.2%)   2.4823 (  1.2%)  Eliminate PHI nodes for register allocation
   2.1927 (  1.1%)   0.0901 (  1.9%)   2.2829 (  1.1%)   2.2829 (  1.1%)  Greedy Register Allocator

It makes isel look good!