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authorReid Kleckner <rnk@google.com>2019-12-02 13:15:30 -0800
committerReid Kleckner <rnk@google.com>2019-12-06 12:58:54 -0800
commitc089f0289856b8f72b06c30daa7848e431c8e36e (patch)
treee92c1fde3bd3af18b16917e16d32ce4c0c55b739 /lldb/packages/Python/lldbsuite/test/commands/expression/call-function/TestCallStdStringFunction.py
parenta7bdab2e9d59ba0fdf06390f4ddadfd00fe50f2e (diff)
downloadbcm5719-llvm-c089f0289856b8f72b06c30daa7848e431c8e36e.tar.gz
bcm5719-llvm-c089f0289856b8f72b06c30daa7848e431c8e36e.zip
[X86] Don't setup and teardown memory for a musttail call
Summary: musttail calls should not require allocating extra stack for arguments. Updates to arguments passed in memory should happen in place before the epilogue. This bug was mostly a missed optimization, unless inalloca was used and store to push conversion fired. If a reserved call frame was used for an inalloca musttail call, the call setup and teardown instructions would be deleted, and SP adjustments would be inserted in the prologue and epilogue. You can see these are removed from several test cases in this change. In the case where the stack frame was not reserved, i.e. call frame optimization fires and turns argument stores into pushes, then the imbalanced call frame setup instructions created for inalloca calls become a problem. They remain in the instruction stream, resulting in a call setup that allocates zero bytes (expected for inalloca), and a call teardown that deallocates the inalloca pack. This deallocation was unbalanced, leading to subsequent crashes. Reviewers: hans Subscribers: hiraditya, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D71097
Diffstat (limited to 'lldb/packages/Python/lldbsuite/test/commands/expression/call-function/TestCallStdStringFunction.py')
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