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243702b95a
accumulator instead of its sub-registers, $hi and $lo. We need this change to prevent a mflo following a mtlo from reading an unpredictable/undefined value, as shown in the following example: mult $6, $7 // result of $6 * $7 is written to $lo and $hi. mflo $2 // read lower 32-bit result from $lo. mtlo $4 // write to $lo. the content of $hi becomes unpredictable. mfhi $3 // read higher 32-bit from $hi, which has an unpredictable value. I don't have a test case for this change that reliably reproduces the problem. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192119 91177308-0d34-0410-b5e6-96231b3b80d8
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