[llvm] r315285 - Fix for PR34888.

Nemanja Ivanovic via llvm-commits llvm-commits at lists.llvm.org
Tue Oct 10 01:46:10 PDT 2017 

Author: nemanjai
Date: Tue Oct 10 01:46:10 2017
New Revision: 315285

URL: http://llvm.org/viewvc/llvm-project?rev=315285&view=rev
Log:
Fix for PR34888.

The issue is that we assume operand zero of the input to the add instruction
is a register. In this case, the input comes from inline assembly and
operand zero is not a register thereby causing a crash.
The code will bail anyway if the input instruction doesn't have the right
opcode. So do that check first and let short-circuiting prevent the crash.

Added:
    llvm/trunk/test/CodeGen/PowerPC/PR3488.ll
Modified:
    llvm/trunk/lib/Target/PowerPC/PPCMIPeephole.cpp

Modified: llvm/trunk/lib/Target/PowerPC/PPCMIPeephole.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/PPCMIPeephole.cpp?rev=315285&r1=315284&r2=315285&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PowerPC/PPCMIPeephole.cpp (original)
+++ llvm/trunk/lib/Target/PowerPC/PPCMIPeephole.cpp Tue Oct 10 01:46:10 2017
@@ -394,9 +394,10 @@ bool PPCMIPeephole::simplifyCode(void) {
           for (unsigned i = 1; i < DefPhiMI->getNumOperands(); i += 2) {
             MachineInstr *LiMI =
                 getVRegDefOrNull(&DefPhiMI->getOperand(i), MRI);
-            if (!LiMI || !MRI->hasOneNonDBGUse(LiMI->getOperand(0).getReg()) ||
-                !MDT->dominates(DefDomMI, LiMI) ||
-                (LiMI->getOpcode() != PPC::LI && LiMI->getOpcode() != PPC::LI8))
+            if (!LiMI ||
+                (LiMI->getOpcode() != PPC::LI && LiMI->getOpcode() != PPC::LI8)
+                || !MRI->hasOneNonDBGUse(LiMI->getOperand(0).getReg()) ||
+                !MDT->dominates(DefDomMI, LiMI))
               return false;
           }
 

Added: llvm/trunk/test/CodeGen/PowerPC/PR3488.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/PowerPC/PR3488.ll?rev=315285&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/PowerPC/PR3488.ll (added)
+++ llvm/trunk/test/CodeGen/PowerPC/PR3488.ll Tue Oct 10 01:46:10 2017
@@ -0,0 +1,121 @@
+; RUN: llc < %s -mtriple=powerpc64le-unknown-unknown -verify-machineinstrs \
+; RUN:   -mcpu=pwr8 | FileCheck %s
+module asm "\09.section \22___kcrctab+numa_node\22, \22a\22\09"
+module asm "\09.weak\09__crc_numa_node\09"
+module asm "\09.long\09__crc_numa_node\09"
+module asm "\09.previous\09\09\09\09\09"
+module asm "\09.section \22___kcrctab+_numa_mem_\22, \22a\22\09"
+module asm "\09.weak\09__crc__numa_mem_\09"
+module asm "\09.long\09__crc__numa_mem_\09"
+module asm "\09.previous\09\09\09\09\09"
+module asm "\09.section \22___kcrctab+node_states\22, \22a\22\09"
+module asm "\09.weak\09__crc_node_states\09"
+module asm "\09.long\09__crc_node_states\09"
+module asm "\09.previous\09\09\09\09\09"
+module asm "\09.section \22___kcrctab+totalram_pages\22, \22a\22\09"
+module asm "\09.weak\09__crc_totalram_pages\09"
+module asm "\09.long\09__crc_totalram_pages\09"
+module asm "\09.previous\09\09\09\09\09"
+module asm "\09.section \22___kcrctab+movable_zone\22, \22a\22\09"
+module asm "\09.weak\09__crc_movable_zone\09"
+module asm "\09.long\09__crc_movable_zone\09"
+module asm "\09.previous\09\09\09\09\09"
+module asm "\09.section \22___kcrctab+nr_node_ids\22, \22a\22\09"
+module asm "\09.weak\09__crc_nr_node_ids\09"
+module asm "\09.long\09__crc_nr_node_ids\09"
+module asm "\09.previous\09\09\09\09\09"
+module asm "\09.section \22___kcrctab+nr_online_nodes\22, \22a\22\09"
+module asm "\09.weak\09__crc_nr_online_nodes\09"
+module asm "\09.long\09__crc_nr_online_nodes\09"
+module asm "\09.previous\09\09\09\09\09"
+module asm "\09.section \22___kcrctab_gpl+split_page\22, \22a\22\09"
+module asm "\09.weak\09__crc_split_page\09"
+module asm "\09.long\09__crc_split_page\09"
+module asm "\09.previous\09\09\09\09\09"
+module asm "\09.section \22___kcrctab+__alloc_pages_nodemask\22, \22a\22\09"
+module asm "\09.weak\09__crc___alloc_pages_nodemask\09"
+module asm "\09.long\09__crc___alloc_pages_nodemask\09"
+module asm "\09.previous\09\09\09\09\09"
+module asm "\09.section \22___kcrctab+__get_free_pages\22, \22a\22\09"
+module asm "\09.weak\09__crc___get_free_pages\09"
+module asm "\09.long\09__crc___get_free_pages\09"
+module asm "\09.previous\09\09\09\09\09"
+module asm "\09.section \22___kcrctab+get_zeroed_page\22, \22a\22\09"
+module asm "\09.weak\09__crc_get_zeroed_page\09"
+module asm "\09.long\09__crc_get_zeroed_page\09"
+module asm "\09.previous\09\09\09\09\09"
+module asm "\09.section \22___kcrctab+__free_pages\22, \22a\22\09"
+module asm "\09.weak\09__crc___free_pages\09"
+module asm "\09.long\09__crc___free_pages\09"
+module asm "\09.previous\09\09\09\09\09"
+module asm "\09.section \22___kcrctab+free_pages\22, \22a\22\09"
+module asm "\09.weak\09__crc_free_pages\09"
+module asm "\09.long\09__crc_free_pages\09"
+module asm "\09.previous\09\09\09\09\09"
+module asm "\09.section \22___kcrctab+__page_frag_cache_drain\22, \22a\22\09"
+module asm "\09.weak\09__crc___page_frag_cache_drain\09"
+module asm "\09.long\09__crc___page_frag_cache_drain\09"
+module asm "\09.previous\09\09\09\09\09"
+module asm "\09.section \22___kcrctab+page_frag_alloc\22, \22a\22\09"
+module asm "\09.weak\09__crc_page_frag_alloc\09"
+module asm "\09.long\09__crc_page_frag_alloc\09"
+module asm "\09.previous\09\09\09\09\09"
+module asm "\09.section \22___kcrctab+page_frag_free\22, \22a\22\09"
+module asm "\09.weak\09__crc_page_frag_free\09"
+module asm "\09.long\09__crc_page_frag_free\09"
+module asm "\09.previous\09\09\09\09\09"
+module asm "\09.section \22___kcrctab+alloc_pages_exact\22, \22a\22\09"
+module asm "\09.weak\09__crc_alloc_pages_exact\09"
+module asm "\09.long\09__crc_alloc_pages_exact\09"
+module asm "\09.previous\09\09\09\09\09"
+module asm "\09.section \22___kcrctab+free_pages_exact\22, \22a\22\09"
+module asm "\09.weak\09__crc_free_pages_exact\09"
+module asm "\09.long\09__crc_free_pages_exact\09"
+module asm "\09.previous\09\09\09\09\09"
+module asm "\09.section \22___kcrctab_gpl+nr_free_buffer_pages\22, \22a\22\09"
+module asm "\09.weak\09__crc_nr_free_buffer_pages\09"
+module asm "\09.long\09__crc_nr_free_buffer_pages\09"
+module asm "\09.previous\09\09\09\09\09"
+module asm "\09.section \22___kcrctab_gpl+si_mem_available\22, \22a\22\09"
+module asm "\09.weak\09__crc_si_mem_available\09"
+module asm "\09.long\09__crc_si_mem_available\09"
+module asm "\09.previous\09\09\09\09\09"
+module asm "\09.section \22___kcrctab+si_meminfo\22, \22a\22\09"
+module asm "\09.weak\09__crc_si_meminfo\09"
+module asm "\09.long\09__crc_si_meminfo\09"
+module asm "\09.previous\09\09\09\09\09"
+module asm "\09.section \22___kcrctab+adjust_managed_page_count\22, \22a\22\09"
+module asm "\09.weak\09__crc_adjust_managed_page_count\09"
+module asm "\09.long\09__crc_adjust_managed_page_count\09"
+module asm "\09.previous\09\09\09\09\09"
+module asm "\09.section \22___kcrctab+free_reserved_area\22, \22a\22\09"
+module asm "\09.weak\09__crc_free_reserved_area\09"
+module asm "\09.long\09__crc_free_reserved_area\09"
+module asm "\09.previous\09\09\09\09\09"
+
+ at nr_cpu_ids = external local_unnamed_addr global i32, align 4
+
+; Function Attrs: nounwind
+define void @__alloc_pages_nodemask() #0 {
+entry:
+  %0 = call i64 asm sideeffect "ld${1:U}${1:X} $0,$1", "=r,*m"(i64* undef)
+  br i1 undef, label %do.body.lr.ph.i.i.i, label %zone_page_state_snapshot.exit.i.i
+; CHECK: ld 3, 0(3)
+
+do.body.lr.ph.i.i.i:                              ; preds = %entry
+  br label %do.body.i.i.i
+
+do.body.i.i.i:                                    ; preds = %do.body.i.i.i, %do.body.lr.ph.i.i.i
+  %x.022.i.i.i = phi i64 [ %0, %do.body.lr.ph.i.i.i ], [ %add7.i.i.i, %do.body.i.i.i ]
+  %1 = load i8, i8* undef, align 1
+  %conv.i.i458.i = sext i8 %1 to i64
+  %add7.i.i.i = add i64 %x.022.i.i.i, %conv.i.i458.i
+  %2 = load i32, i32* @nr_cpu_ids, align 4
+  %cmp.i1.i.i = icmp ult i32 0, %2
+  br i1 %cmp.i1.i.i, label %do.body.i.i.i, label %zone_page_state_snapshot.exit.i.i
+
+zone_page_state_snapshot.exit.i.i:                ; preds = %do.body.i.i.i, %entry
+  %x.0.lcssa.i.i.i = phi i64 [ %0, %entry ], [ %add7.i.i.i, %do.body.i.i.i ]
+  %3 = icmp sgt i64 %x.0.lcssa.i.i.i, 0
+  unreachable
+}

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