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[MIPS] Emitted instructions do not meet their predicates #30062

Open llvmbot opened 8 years ago

llvmbot commented 8 years ago
Bugzilla Link 30714
Version trunk
OS All
Reporter LLVM Bugzilla Contributor

Extended Description

Certain instructions can be emitted in cases where they do not meet their predicates.

See: https://reviews.llvm.org/D25618 and https://reviews.llvm.org/D25622

Quoting D25622:

The following tests fail when this patch is applied. Failing Tests (26):

LLVM :: CodeGen/Mips/cconv/callee-saved-float.ll LLVM :: CodeGen/Mips/micromips-atomic1.ll LLVM :: CodeGen/Mips/tailcall/tailcall-wrong-isa.ll LLVM :: MC/Mips/cprestore-noreorder.s LLVM :: MC/Mips/cprestore-reorder.s LLVM :: MC/Mips/elf_eflags_mips16.s LLVM :: MC/Mips/expansion-jal-sym-pic.s LLVM :: MC/Mips/expr1.s LLVM :: MC/Mips/micromips-16-bit-instructions.s LLVM :: MC/Mips/micromips-alu-instructions.s LLVM :: MC/Mips/micromips-branch-fixup.s LLVM :: MC/Mips/micromips-branch-instructions.s LLVM :: MC/Mips/micromips-control-instructions.s LLVM :: MC/Mips/micromips-dsp/valid-micromips32r3.s LLVM :: MC/Mips/micromips-el-fixup-data.s LLVM :: MC/Mips/micromips-expansions.s LLVM :: MC/Mips/micromips-fpu-instructions.s LLVM :: MC/Mips/micromips-jump-instructions.s LLVM :: MC/Mips/micromips-jump26.s LLVM :: MC/Mips/micromips-tailr.s LLVM :: MC/Mips/micromips/valid.s LLVM :: MC/Mips/micromips32r6/valid.s LLVM :: MC/Mips/mips2/valid.s LLVM :: MC/Mips/mips3/valid.s LLVM :: MC/Mips/mips4/valid.s LLVM :: MC/Mips/mips5/valid.s

Some look like bugs but others look like they are deliberate (e.g. SYNC is using a loophole to implement the MIPS-II version as an alias of the MIPS32 version).

llvmbot commented 6 years ago

What is happening with this bug? Patch from D25622 needs update, as it is now it can not be applied.

llvmbot commented 8 years ago

Looking through the failing tests points to mixed MIPS / (microMIPS | mips16e) triggering the test failures.

There's few places in the backend where we emit only standard MIPS. Some of the cases care cprestore expansion, nop insertion in the target streamer.

The some of the other tests are showing that the instructions in question are not covered by NotInMicroMips predicate.

Cases: sdbbp (no operand alias), cache, pref, ssnop, ehb, pause, break (no operand alias and one operand alias).

llvmbot commented 8 years ago

Sync fixed in r284483.