[PATCH] D114636: [ARM] Correct range in isLegalAddressImm

[Dave Green via Phabricator via llvm-commits]

dmgreen created this revision.
dmgreen added reviewers: SjoerdMeijer, samtebbs, simon_tatham, ostannard.
Herald added subscribers: hiraditya, kristof.beyls.
dmgreen requested review of this revision.
Herald added a project: LLVM.

The ranges in isLegalAddressImm were off by one, not allowing the maximum values for unscaled offsets.


https://reviews.llvm.org/D114636

Files:
  llvm/lib/Target/ARM/ARMBaseInstrInfo.h
  llvm/test/CodeGen/Thumb2/store-prepostinc.mir


Index: llvm/test/CodeGen/Thumb2/store-prepostinc.mir
===================================================================
--- llvm/test/CodeGen/Thumb2/store-prepostinc.mir
+++ llvm/test/CodeGen/Thumb2/store-prepostinc.mir
@@ -460,8 +460,7 @@
     ; CHECK-LABEL: name: STR_post255
     ; CHECK: liveins: $r0, $r1
     ; CHECK-NEXT: {{  $}}
-    ; CHECK-NEXT: t2STRi12 killed renamable $r1, renamable $r0, 0, 14 /* CC::al */, $noreg :: (store (s32))
-    ; CHECK-NEXT: renamable $r0 = nuw t2ADDri killed renamable $r0, 255, 14 /* CC::al */, $noreg, $noreg
+    ; CHECK-NEXT: early-clobber $r0 = t2STR_POST killed $r1, $r0, 255, 14 /* CC::al */, $noreg :: (store (s32))
     ; CHECK-NEXT: tBX_RET 14 /* CC::al */, $noreg, implicit $r0
     t2STRi12 killed renamable $r1, renamable $r0, 0, 14 /* CC::al */, $noreg :: (store (s32))
     renamable $r0 = nuw t2ADDri killed renamable $r0, 255, 14 /* CC::al */, $noreg, $noreg
Index: llvm/lib/Target/ARM/ARMBaseInstrInfo.h
===================================================================
--- llvm/lib/Target/ARM/ARMBaseInstrInfo.h
+++ llvm/lib/Target/ARM/ARMBaseInstrInfo.h
@@ -877,19 +877,19 @@
   unsigned AddrMode = (Desc.TSFlags & ARMII::AddrModeMask);
   switch (AddrMode) {
   case ARMII::AddrModeT2_i7:
-    return std::abs(Imm) < (((1 << 7) * 1) - 1);
+    return std::abs(Imm) < ((1 << 7) * 1);
   case ARMII::AddrModeT2_i7s2:
-    return std::abs(Imm) < (((1 << 7) * 2) - 1) && Imm % 2 == 0;
+    return std::abs(Imm) < ((1 << 7) * 2) && Imm % 2 == 0;
   case ARMII::AddrModeT2_i7s4:
-    return std::abs(Imm) < (((1 << 7) * 4) - 1) && Imm % 4 == 0;
+    return std::abs(Imm) < ((1 << 7) * 4) && Imm % 4 == 0;
   case ARMII::AddrModeT2_i8:
-    return std::abs(Imm) < (((1 << 8) * 1) - 1);
-  case ARMII::AddrMode2:
-    return std::abs(Imm) < (((1 << 12) * 1) - 1);
-  case ARMII::AddrModeT2_i12:
-    return Imm >= 0 && Imm < (((1 << 12) * 1) - 1);
+    return std::abs(Imm) < ((1 << 8) * 1);
   case ARMII::AddrModeT2_i8s4:
-    return std::abs(Imm) < (((1 << 8) * 4) - 1) && Imm % 4 == 0;
+    return std::abs(Imm) < ((1 << 8) * 4) && Imm % 4 == 0;
+  case ARMII::AddrModeT2_i12:
+    return Imm >= 0 && Imm < ((1 << 12) * 1);
+  case ARMII::AddrMode2:
+    return std::abs(Imm) < ((1 << 12) * 1);
   default:
     llvm_unreachable("Unhandled Addressing mode");
   }


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