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| author | Arthur Eubanks <aeubanks@google.com> | 2022-06-30 15:18:04 -0700 |
|---|---|---|
| committer | Arthur Eubanks <aeubanks@google.com> | 2022-07-26 08:01:08 -0700 |
| commit | 2eade1dba4a8d6e1c6867e9127bcd88cf4e55976 (patch) | |
| tree | 080ccfec588a3231d14022bc922f5c05e9a11adb /llvm/lib/IR/ModuleSummaryIndex.cpp | |
| parent | e43621b09c9741d2e3a8a3d8ed216699af5ff8ba (diff) | |
| download | llvm-2eade1dba4a8d6e1c6867e9127bcd88cf4e55976.zip llvm-2eade1dba4a8d6e1c6867e9127bcd88cf4e55976.tar.gz llvm-2eade1dba4a8d6e1c6867e9127bcd88cf4e55976.tar.bz2 | |
[WPD] Use new llvm.public.type.test intrinsic for potentially publicly visible classes
Turning on opaque pointers has uncovered an issue with WPD where we currently pattern match away `assume(type.test)` in WPD so that a later LTT doesn't resolve the type test to undef and introduce an `assume(false)`. The pattern matching can fail in cases where we transform two `assume(type.test)`s into `assume(phi(type.test.1, type.test.2))`.
Currently we create `assume(type.test)` for all virtual calls that might be devirtualized. This is to support `-Wl,--lto-whole-program-visibility`.
To prevent this, all virtual calls that may not be in the same LTO module instead use a new `llvm.public.type.test` intrinsic in place of the `llvm.type.test`. Then when we know if `-Wl,--lto-whole-program-visibility` is passed or not, we can either replace all `llvm.public.type.test` with `llvm.type.test`, or replace all `llvm.public.type.test` with `true`. This prevents WPD from trying to pattern match away `assume(type.test)` for public virtual calls when failing the pattern matching will result in miscompiles.
Reviewed By: tejohnson
Differential Revision: https://reviews.llvm.org/D128955
Diffstat (limited to 'llvm/lib/IR/ModuleSummaryIndex.cpp')
| -rw-r--r-- | llvm/lib/IR/ModuleSummaryIndex.cpp | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/llvm/lib/IR/ModuleSummaryIndex.cpp b/llvm/lib/IR/ModuleSummaryIndex.cpp index 0ca40a6..3e82987 100644 --- a/llvm/lib/IR/ModuleSummaryIndex.cpp +++ b/llvm/lib/IR/ModuleSummaryIndex.cpp @@ -105,11 +105,13 @@ uint64_t ModuleSummaryIndex::getFlags() const { Flags |= 0x20; if (withDSOLocalPropagation()) Flags |= 0x40; + if (withWholeProgramVisibility()) + Flags |= 0x80; return Flags; } void ModuleSummaryIndex::setFlags(uint64_t Flags) { - assert(Flags <= 0x7f && "Unexpected bits in flag"); + assert(Flags <= 0xff && "Unexpected bits in flag"); // 1 bit: WithGlobalValueDeadStripping flag. // Set on combined index only. if (Flags & 0x1) @@ -139,6 +141,10 @@ void ModuleSummaryIndex::setFlags(uint64_t Flags) { // Set on combined index only. if (Flags & 0x40) setWithDSOLocalPropagation(); + // 1 bit: WithWholeProgramVisibility flag. + // Set on combined index only. + if (Flags & 0x80) + setWithWholeProgramVisibility(); } // Collect for the given module the list of function it defines |