[AArch64] Disable AArch64StorePairSuppress under optsize

[dmgreen]

Summary

AArch64StorePairSuppress will prevent the creation of LDP's based on scheduling info. This shouldn't apply when optimizing for size though, where the size decrease should be considered more important.

[fhahn]

LGTM, thanks!

llvm/lib/Target/AArch64/AArch64StorePairSuppress.cpp

bool AArch64StorePairSuppress::isNarrowFPStore(const MachineInstr &MI) {
   case AArch64::STRDui:
   case AArch64::STURSi:
   case AArch64::STURDi:
     return true;
   }
 }
 
 bool AArch64StorePairSuppress::runOnMachineFunction(MachineFunction &MF) {
-  if (skipFunction(MF.getFunction()))
+  if (skipFunction(MF.getFunction()) || MF.getFunction().hasOptSize())
     return false;
 
   const TargetSubtargetInfo &ST = MF.getSubtarget();
   TII = static_cast<const AArch64InstrInfo *>(ST.getInstrInfo());
   TRI = ST.getRegisterInfo();
   MRI = &MF.getRegInfo();
   SchedModel.init(&ST);
   Traces = &getAnalysis<MachineTraceMetrics>();

llvm/test/CodeGen/AArch64/storepairsuppress_minsize.ll

 ; CHECK-LABEL: test_minsize:
 ; CHECK:       // %bb.0:
 ; CHECK-NEXT:    str x30, [sp, #-16]! // 8-byte Folded Spill
 ; CHECK-NEXT:    .cfi_def_cfa_offset 16
 ; CHECK-NEXT:    .cfi_offset w30, -16
 ; CHECK-NEXT:    bl return_in_block
 ; CHECK-NEXT:    adrp x8, in_block_store
 ; CHECK-NEXT:    add x8, x8, :lo12:in_block_store
-; CHECK-NEXT:    str d0, [x8]
-; CHECK-NEXT:    str d1, [x8, #8]
-; CHECK-NEXT:    str d2, [x8, #16]
-; CHECK-NEXT:    str d3, [x8, #24]
-; CHECK-NEXT:    str d4, [x8, #32]
-; CHECK-NEXT:    str d5, [x8, #40]
+; CHECK-NEXT:    stp d0, d1, [x8]
+; CHECK-NEXT:    stp d2, d3, [x8, #16]
+; CHECK-NEXT:    stp d4, d5, [x8, #32]
 ; CHECK-NEXT:    ldr x30, [sp], #16 // 8-byte Folded Reload
 ; CHECK-NEXT:    ret
   %1 = call %T_IN_BLOCK @return_in_block()
   store %T_IN_BLOCK %1, %T_IN_BLOCK* @in_block_store
   ret void
 }
 
 define void @test_optsize() optsize {
 ; CHECK-LABEL: test_optsize:
 ; CHECK:       // %bb.0:
 ; CHECK-NEXT:    str x30, [sp, #-16]! // 8-byte Folded Spill
 ; CHECK-NEXT:    .cfi_def_cfa_offset 16
 ; CHECK-NEXT:    .cfi_offset w30, -16
 ; CHECK-NEXT:    bl return_in_block
 ; CHECK-NEXT:    adrp x8, in_block_store
 ; CHECK-NEXT:    add x8, x8, :lo12:in_block_store
-; CHECK-NEXT:    str d0, [x8]
-; CHECK-NEXT:    str d1, [x8, #8]
-; CHECK-NEXT:    str d2, [x8, #16]
-; CHECK-NEXT:    str d3, [x8, #24]
-; CHECK-NEXT:    str d4, [x8, #32]
-; CHECK-NEXT:    str d5, [x8, #40]
+; CHECK-NEXT:    stp d0, d1, [x8]
+; CHECK-NEXT:    stp d2, d3, [x8, #16]
+; CHECK-NEXT:    stp d4, d5, [x8, #32]
 ; CHECK-NEXT:    ldr x30, [sp], #16 // 8-byte Folded Reload
 ; CHECK-NEXT:    ret
   %1 = call %T_IN_BLOCK @return_in_block()
   store %T_IN_BLOCK %1, %T_IN_BLOCK* @in_block_store
   ret void
 }