[llvm] 24303e3 - [AArch64] Use encodeLogicalImmediate for forming the immediate to an AND. NFC.
Martin Storsjö via llvm-commits
llvm-commits at lists.llvm.org
Wed Oct 12 23:54:37 PDT 2022
Author: Martin Storsjö
Date: 2022-10-13T09:47:38+03:00
New Revision: 24303e3ad2b5bf4eb4a5ef4979f1c4f1d1ae9fa6
URL: https://github.com/llvm/llvm-project/commit/24303e3ad2b5bf4eb4a5ef4979f1c4f1d1ae9fa6
DIFF: https://github.com/llvm/llvm-project/commit/24303e3ad2b5bf4eb4a5ef4979f1c4f1d1ae9fa6.diff
LOG: [AArch64] Use encodeLogicalImmediate for forming the immediate to an AND. NFC.
Differential Revision: https://reviews.llvm.org/D135817
Added:
Modified:
llvm/lib/Target/AArch64/AArch64FrameLowering.cpp
Removed:
################################################################################
diff --git a/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp b/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp
index 9ed87902eec0..336bbb01b198 100644
--- a/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp
+++ b/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp
@@ -1814,24 +1814,18 @@ void AArch64FrameLowering::emitPrologue(MachineFunction &MF,
StackOffset::getFixed((int64_t)MFI.getStackSize() - NumBytes));
}
if (NeedsRealignment) {
- const unsigned NrBitsToZero = Log2(MFI.getMaxAlign());
- assert(NrBitsToZero > 1);
+ assert(MFI.getMaxAlign() > Align(1));
assert(scratchSPReg != AArch64::SP);
// SUB X9, SP, NumBytes
// -- X9 is temporary register, so shouldn't contain any live data here,
// -- free to use. This is already produced by emitFrameOffset above.
// AND SP, X9, 0b11111...0000
- // The logical immediates have a non-trivial encoding. The following
- // formula computes the encoded immediate with all ones but
- // NrBitsToZero zero bits as least significant bits.
- uint32_t andMaskEncoded = (1 << 12) // = N
- | ((64 - NrBitsToZero) << 6) // immr
- | ((64 - NrBitsToZero - 1) << 0); // imms
+ uint64_t AndMask = ~(MFI.getMaxAlign().value() - 1);
BuildMI(MBB, MBBI, DL, TII->get(AArch64::ANDXri), AArch64::SP)
.addReg(scratchSPReg, RegState::Kill)
- .addImm(andMaskEncoded);
+ .addImm(AArch64_AM::encodeLogicalImmediate(AndMask, 64));
AFI->setStackRealigned(true);
// No need for SEH instructions here; if we're realigning the stack,
More information about the llvm-commits
mailing list