[TII] Split isTrivialReMaterializable into two versions [nfc] (#160377)

This change builds on https://github.com/llvm/llvm-project/pull/160319
which tries to clarify which *callers* (not backends) assume that the
result is actually trivial.

This change itself should be NFC. Essentially, I'm just renaming the
existing isTrivialRematerializable to the non-trivial version and then
adding a new trivial version (with the same name as the prior function)
and simplifying a few callers which want that semantic.

This change does *not* enable non-trivial remat any more broadly than
was already done for our targets which were lying through the old APIs;
that will come separately. The goal here is simply to make the code
easier to follow in terms of what assumptions are being made where.

---------

Co-authored-by: Luke Lau <luke_lau@icloud.com>

1 files changed, 1 insertions, 4 deletions

diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyRegStackify.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyRegStackify.cpp
index 7591541..08ca20b5 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyRegStackify.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyRegStackify.cpp
@@ -260,10 +260,7 @@ static void query(const MachineInstr &MI, bool &Read, bool &Write,
 // Test whether Def is safe and profitable to rematerialize.
 static bool shouldRematerialize(const MachineInstr &Def,
                                 const WebAssemblyInstrInfo *TII) {
-  return Def.isAsCheapAsAMove() && TII->isTriviallyReMaterializable(Def) &&
-         llvm::all_of(Def.all_uses(), [](const MachineOperand &MO) {
-           return MO.getReg().isVirtual();
-         });
+  return Def.isAsCheapAsAMove() && TII->isTriviallyReMaterializable(Def);
 }
 
 // Identify the definition for this register at this point. This is a