[LLVMbugs] [Bug 17406] New: SDIV >128bit, DAG->DAG error in LegalizeIntegerTypes

[bugzilla-daemon at llvm.org]

http://llvm.org/bugs/show_bug.cgi?id=17406

            Bug ID: 17406
           Summary: SDIV >128bit, DAG->DAG error in LegalizeIntegerTypes
           Product: new-bugs
           Version: trunk
          Hardware: PC
                OS: Linux
            Status: NEW
          Severity: normal
          Priority: P
         Component: new bugs
          Assignee: unassignedbugs at nondot.org
          Reporter: eda-qa at disemia.com
                CC: llvmbugs at cs.uiuc.edu
    Classification: Unclassified

I'm getting the following error when trying to SDIV integers greater
than 128bit (on an AMD64 target).

LegalizeIntegerTypes.cpp:2047: void
llvm::DAGTypeLegalizer::ExpandIntRes_SDIV(llvm::SDNode*, llvm::SDValue&,
llvm::SDValue&): Assertion `LC != RTLIB::UNKNOWN_LIBCALL && "Unsupported
SDIV!"' failed.
Stack dump:
0.      Running pass 'X86 DAG->DAG Instruction Selection' on function
'@_entry'

However, not all SDIV on such integers fails, the below works:

@a = global i200 undef
@b = global i64 undef

define void @_entry() {
entry:
  store i200 200, i200* @a
  %0 = load i200* @a
  %1 = load i200* @a
  %2 = sdiv i200 %0, %1
  %3 = trunc i200 %2 to i64
  store i64 %3, i64* @b
  %4 = load i64* @b
  call void @trace_integer(i64 %4)
  ret void
}


Yet with a simple addition (the same SDIV) it fails:

define void @_entry() {
entry:
  store i200 200, i200* @a
  %0 = load i200* @a
  %1 = load i200* @a
  %2 = sdiv i200 %0, %1
  %3 = trunc i200 %2 to i64
  store i64 %3, i64* @b
  %4 = load i200* @a
  %5 = load i200* @a
  %6 = sdiv i200 %4, %5
  store i200 %6, i200* @a
  ret void
}


This is on the LLVM 3.3 release (it also happens on 3.2, the reason I updated).
As it appears all integer sizes are intended to be supported I assume this is a
defect.

-- 
You are receiving this mail because:
You are on the CC list for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-bugs/attachments/20130930/807aa5b2/attachment.html>