4 Commits

Author SHA1 Message Date
Matt Arsenault
d9e51e7552 CodeGenPrepare: Convert most tests to opaque pointers
NVPTX/dont-introduce-addrspacecast.ll required manually removing a check for
a bitcast.

AArch64/combine-address-mode.ll required rerunning update_test_checks

Mips required some manual updates due to a CHECK-NEXT coming after a
deleted bitcast.

ARM/sink-addrmode.ll needed one small manual fix.

Excludes one X86 function which needs more attention.
2022-11-28 09:21:59 -05:00
Jann Horn
91c9dee3fb [CodeGenPrepare] Eliminate llvm.expect before removing empty blocks
CodeGenPrepare currently first removes empty blocks, then in a loop
performs other optimizations. One of those optimizations is the removal
of call instructions that invoke @llvm.assume, which can create new
empty blocks.

This means that when a branch only contains a call to __builtin_assume(),
the empty branch will survive into MIR, and will then only be
half-removed by MIR-level optimizations (e.g. removing the branch but
leaving the condition intact).

Fix it by eliminating @llvm.expect builtin calls before removing empty
blocks.

Reviewed By: bkramer

Differential Revision: https://reviews.llvm.org/D97848
2021-03-04 14:48:26 +01:00
Florian Hahn
292077072e
[Local] Treat calls that may not return as being alive.
With the addition of the `willreturn` attribute, functions that may
not return (e.g. due to an infinite loop) are well defined, if they are
not marked as `willreturn`.

This patch updates `wouldInstructionBeTriviallyDead` to not consider
calls that may not return as dead.

This patch still provides an escape hatch for intrinsics, which are
still assumed as willreturn unconditionally. It will be removed once
all intrinsics definitions have been reviewed and updated.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D94106
2021-01-23 16:05:14 +00:00
Benjamin Kramer
52cc97a0db [CodeGenPrepare] Zap the argument of llvm.assume when deleting it
We know that the argument is mostly likely dead, so we can purge it
early. Otherwise it would make it to codegen, and can block further
optimizations.
2020-08-28 20:52:22 +02:00