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Revert "[MIRPrinter] Print empty successor lists when they cannot be guessed" 

This reverts commit r313685.

I thought I had ran ninja check, but apparently I didn't...
Need to update a bunch of mir tests.

llvm-svn: 313686
This commit is contained in:
Quentin Colombet 2017-09-19 22:03:50 +00:00
parent 7fdaa5e641
commit 6888dbcda7
2 changed files with 2 additions and 49 deletions
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3
llvm/lib/CodeGen/MIRPrinter.cpp
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@ -598,7 +598,8 @@ void MIPrinter::print(const MachineBasicBlock &MBB) {
bool HasLineAttributes = false;
// Print the successors
bool canPredictProbs = canPredictBranchProbabilities(MBB);
if (!SimplifyMIR || !canPredictProbs || !canPredictSuccessors(MBB)) {
if (!MBB.succ_empty() && (!SimplifyMIR || !canPredictProbs ||
!canPredictSuccessors(MBB))) {
OS.indent(2) << "successors: ";
for (auto I = MBB.succ_begin(), E = MBB.succ_end(); I != E; ++I) {
if (I != MBB.succ_begin())

48
llvm/test/CodeGen/MIR/X86/unreachable_block.ll
View File

@ -1,48 +0,0 @@
; RUN: llc -mtriple x86_64-- -stop-before peephole-opt -o %t.mir %s
; RUN: llc -mtriple x86_64-- -run-pass none %t.mir -verify-machineinstrs -o - | FileCheck %s
; Unreachable blocks in the machine instr representation are these
; weird empty blocks with no successors.
; The MIR printer used to not print empty lists of successors. However,
; the MIR parser now treats non-printed list of successors as "please
; guess it for me". As a result, the parser tries to guess the list of
; successors and given the block is empty, just assumes it falls through
; the next block.
;
; The following test case used to fail the verifier because the false
; path ended up falling through split.true and now, the definition of
; %v does not dominate all its uses.
; Indeed, we go from the following CFG:
; entry
; / \
; true (def) false
; |
; split.true (use)
;
; To this one:
; entry
; / \
; true (def) false
; | / <-- invalid edge
; split.true (use)
;
; Because of the invalid edge, we get the "def does not
; dominate all uses" error.
;
; CHECK-LABEL: name: foo
; CHECK-LABEL: bb.{{[0-9]+}}.false:
; CHECK-NEXT: successors:
; CHECK-NOT: %bb.{{[0-9]+}}.split.true
; CHECK-LABEL: bb.{{[0-9]+}}.split.true:
define void @foo(i32* %bar) {
br i1 undef, label %true, label %false
true:
%v = load i32, i32* %bar
br label %split.true
false:
unreachable
split.true:
%vInc = add i32 %v, 1
store i32 %vInc, i32* %bar
ret void
}