[AArch64] Prefer "mov" over "orr" to materialize constants.
This is generally more readable due to the way the assembler aliases
work.
(This causes a lot of test changes, but it's not really as scary as it
looks at first glance; it's just mechanically changing a bunch of checks
for orr to check for mov instead.)
Differential Revision: https://reviews.llvm.org/D59720
llvm-svn: 356954
diff --git a/llvm/lib/Target/AArch64/AArch64ExpandImm.cpp b/llvm/lib/Target/AArch64/AArch64ExpandImm.cpp
index c8602da..c764af8 100644
--- a/llvm/lib/Target/AArch64/AArch64ExpandImm.cpp
+++ b/llvm/lib/Target/AArch64/AArch64ExpandImm.cpp
@@ -318,8 +318,11 @@
ZeroChunks++;
}
- // FIXME: Prefer MOVZ/MOVN over ORR because of the rules for the "mov"
- // alias.
+ // Prefer MOVZ/MOVN over ORR because of the rules for the "mov" alias.
+ if ((BitSize / 16) - OneChunks <= 1 || (BitSize / 16) - ZeroChunks <= 1) {
+ expandMOVImmSimple(Imm, BitSize, OneChunks, ZeroChunks, Insn);
+ return;
+ }
// Try a single ORR.
uint64_t UImm = Imm << (64 - BitSize) >> (64 - BitSize);