From 8585e9d33dfd6b8b4143ea77014c2c3f15f0693b Mon Sep 17 00:00:00 2001 From: Eli Friedman Date: Fri, 12 Aug 2016 20:28:02 +0000 Subject: [AArch64LoadStoreOpt] Handle offsets correctly for post-indexed paired loads. Trunk would try to create something like "stp x9, x8, [x0], #512", which isn't actually a valid instruction. Differential revision: https://reviews.llvm.org/D23368 llvm-svn: 278559 --- llvm/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'llvm/lib') diff --git a/llvm/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp b/llvm/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp index 3b2277b7996..a2e0376c50b 100644 --- a/llvm/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp +++ b/llvm/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp @@ -1419,9 +1419,6 @@ bool AArch64LoadStoreOpt::isMatchingUpdateInsn(MachineInstr &MemMI, default: break; case AArch64::SUBXri: - // Negate the offset for a SUB instruction. - Offset *= -1; - // FALLTHROUGH case AArch64::ADDXri: // Make sure it's a vanilla immediate operand, not a relocation or // anything else we can't handle. @@ -1439,6 +1436,9 @@ bool AArch64LoadStoreOpt::isMatchingUpdateInsn(MachineInstr &MemMI, bool IsPairedInsn = isPairedLdSt(MemMI); int UpdateOffset = MI.getOperand(2).getImm(); + if (MI.getOpcode() == AArch64::SUBXri) + UpdateOffset = -UpdateOffset; + // For non-paired load/store instructions, the immediate must fit in a // signed 9-bit integer. if (!IsPairedInsn && (UpdateOffset > 255 || UpdateOffset < -256)) @@ -1453,13 +1453,13 @@ bool AArch64LoadStoreOpt::isMatchingUpdateInsn(MachineInstr &MemMI, break; int ScaledOffset = UpdateOffset / Scale; - if (ScaledOffset > 64 || ScaledOffset < -64) + if (ScaledOffset > 63 || ScaledOffset < -64) break; } // If we have a non-zero Offset, we check that it matches the amount // we're adding to the register. - if (!Offset || Offset == MI.getOperand(2).getImm()) + if (!Offset || Offset == UpdateOffset) return true; break; } -- cgit v1.2.3