Index: llvm/trunk/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp =================================================================== --- llvm/trunk/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp +++ llvm/trunk/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp @@ -866,9 +866,11 @@ .addImm(Imms); } } - StoreI->clearRegisterKills(StRt, TRI); - (void)BitExtMI; + // Clear kill flags between store and load. + for (MachineInstr &MI : make_range(StoreI->getIterator(), + BitExtMI->getIterator())) + MI.clearRegisterKills(StRt, TRI); DEBUG(dbgs() << "Promoting load by replacing :\n "); DEBUG(StoreI->print(dbgs())); Index: llvm/trunk/test/CodeGen/AArch64/ldst-opt.mir =================================================================== --- llvm/trunk/test/CodeGen/AArch64/ldst-opt.mir +++ llvm/trunk/test/CodeGen/AArch64/ldst-opt.mir @@ -1,10 +1,4 @@ # RUN: llc -mtriple=aarch64--linux-gnu -run-pass=aarch64-ldst-opt %s -verify-machineinstrs -o - 2>&1 | FileCheck %s ---- | - define void @promote-load-from-store() { ret void } - define void @store-pair() { ret void } - define void @store-pair-clearkill0() { ret void } - define void @store-pair-clearkill1() { ret void } -... --- name: promote-load-from-store tracksRegLiveness: true @@ -130,3 +124,23 @@ # CHECK-NOT: %w2 = COPY killed %w1 # CHECK: %w2 = COPY %w1 # CHECK: STPWi %w1, killed %w2, killed %x0, 0 +--- +name: store-load-clearkill +tracksRegLiveness: true +body: | + bb.0: + liveins: %w1 + + STRWui %w1, %sp, 0 :: (store 4) + %wzr = COPY killed %w1 ; killing use of %w1 + %w11 = LDRWui %sp, 0 :: (load 4) + HINT 0, implicit %w11 ; some use of %w11 +... +# When replaceing the load of a store-load pair with a copy the kill flags +# along the way need to be cleared. +# CHECK-LABEL: name: store-load-clearkill +# CHECK: STRWui %w1, %sp, 0 :: (store 4) +# CHECK-NOT: COPY killed %w1 +# CHECK: %wzr = COPY %w1 +# CHECK: %w11 = ORRWrs %wzr, %w1, 0 +# CHECK: HINT 0, implicit %w11