[llvm] 8172ed9 - [X86] Speculatively fix to X86AvoidStoreForwardingBlocks not deference a machine mem operand if there isn't one present.

[Craig Topper via llvm-commits]

Author: Craig Topper
Date: 2020-06-24T00:13:58-07:00
New Revision: 8172ed91f8ff753fb3042f39b0d43aed89fdd3e6

URL: https://github.com/llvm/llvm-project/commit/8172ed91f8ff753fb3042f39b0d43aed89fdd3e6
DIFF: https://github.com/llvm/llvm-project/commit/8172ed91f8ff753fb3042f39b0d43aed89fdd3e6.diff

LOG: [X86] Speculatively fix to X86AvoidStoreForwardingBlocks not deference a machine mem operand if there isn't one present.

Eric Christopher informed me that FastISel memcpy handling creates
load/store instructions without mem operands. We should fix that,
but I doubt that's the only case of missed mem operands so seems
better to be defensive here.

I don't have a test case yet, but I'll try to add one if i get a
test from Eric.

Added: 
    

Modified: 
    llvm/lib/Target/X86/X86AvoidStoreForwardingBlocks.cpp

Removed: 
    


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diff  --git a/llvm/lib/Target/X86/X86AvoidStoreForwardingBlocks.cpp b/llvm/lib/Target/X86/X86AvoidStoreForwardingBlocks.cpp
index 2a37b72956e9..9f1fece1b9dd 100644
--- a/llvm/lib/Target/X86/X86AvoidStoreForwardingBlocks.cpp
+++ b/llvm/lib/Target/X86/X86AvoidStoreForwardingBlocks.cpp
@@ -551,11 +551,8 @@ void X86AvoidSFBPass::findPotentiallylBlockedCopies(MachineFunction &MF) {
         if (StoreMI.getParent() == MI.getParent() &&
             isPotentialBlockedMemCpyPair(MI.getOpcode(), StoreMI.getOpcode()) &&
             isRelevantAddressingMode(&MI) &&
-            isRelevantAddressingMode(&StoreMI)) {
-          assert(MI.hasOneMemOperand() &&
-                 "Expected one memory operand for load instruction");
-          assert(StoreMI.hasOneMemOperand() &&
-                 "Expected one memory operand for store instruction");
+            isRelevantAddressingMode(&StoreMI) &&
+            MI.hasOneMemOperand() && StoreMI.hasOneMemOperand()) {
           if (!alias(**MI.memoperands_begin(), **StoreMI.memoperands_begin()))
             BlockedLoadsStoresPairs.push_back(std::make_pair(&MI, &StoreMI));
         }
@@ -695,10 +692,9 @@ bool X86AvoidSFBPass::runOnMachineFunction(MachineFunction &MF) {
     for (auto *PBInst : PotentialBlockers) {
       if (!isPotentialBlockingStoreInst(PBInst->getOpcode(),
                                         LoadInst->getOpcode()) ||
-          !isRelevantAddressingMode(PBInst))
+          !isRelevantAddressingMode(PBInst) || !PBInst->hasOneMemOperand())
         continue;
       int64_t PBstDispImm = getDispOperand(PBInst).getImm();
-      assert(PBInst->hasOneMemOperand() && "Expected One Memory Operand");
       unsigned PBstSize = (*PBInst->memoperands_begin())->getSize();
       // This check doesn't cover all cases, but it will suffice for now.
       // TODO: take branch probability into consideration, if the blocking