[llvm] r221157 - [AArch64] Fix miscompile of comparison with 0xffffffffffffffff

[Oliver Stannard]

Author: olista01
Date: Mon Nov  3 09:28:40 2014
New Revision: 221157

URL: http://llvm.org/viewvc/llvm-project?rev=221157&view=rev
Log:
[AArch64] Fix miscompile of comparison with 0xffffffffffffffff

Some literals in the AArch64 backend had 15 'f's rather than 16, causing
comparisons with a constant 0xffffffffffffffff to be miscompiled.


Added:
    llvm/trunk/test/CodeGen/AArch64/cmp-const-max.ll
Modified:
    llvm/trunk/lib/Target/AArch64/AArch64ISelLowering.cpp

Modified: llvm/trunk/lib/Target/AArch64/AArch64ISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AArch64/AArch64ISelLowering.cpp?rev=221157&r1=221156&r2=221157&view=diff
==============================================================================
--- llvm/trunk/lib/Target/AArch64/AArch64ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/AArch64/AArch64ISelLowering.cpp Mon Nov  3 09:28:40 2014
@@ -1158,9 +1158,9 @@ static SDValue getAArch64Cmp(SDValue LHS
         break;
       case ISD::SETLE:
       case ISD::SETGT:
-        if ((VT == MVT::i32 && C != 0x7fffffff &&
+        if ((VT == MVT::i32 && C != INT32_MAX &&
              isLegalArithImmed((uint32_t)(C + 1))) ||
-            (VT == MVT::i64 && C != 0x7ffffffffffffffULL &&
+            (VT == MVT::i64 && C != INT64_MAX &&
              isLegalArithImmed(C + 1ULL))) {
           CC = (CC == ISD::SETLE) ? ISD::SETLT : ISD::SETGE;
           C = (VT == MVT::i32) ? (uint32_t)(C + 1) : C + 1;
@@ -1169,9 +1169,9 @@ static SDValue getAArch64Cmp(SDValue LHS
         break;
       case ISD::SETULE:
       case ISD::SETUGT:
-        if ((VT == MVT::i32 && C != 0xffffffff &&
+        if ((VT == MVT::i32 && C != UINT32_MAX &&
              isLegalArithImmed((uint32_t)(C + 1))) ||
-            (VT == MVT::i64 && C != 0xfffffffffffffffULL &&
+            (VT == MVT::i64 && C != UINT64_MAX &&
              isLegalArithImmed(C + 1ULL))) {
           CC = (CC == ISD::SETULE) ? ISD::SETULT : ISD::SETUGE;
           C = (VT == MVT::i32) ? (uint32_t)(C + 1) : C + 1;

Added: llvm/trunk/test/CodeGen/AArch64/cmp-const-max.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AArch64/cmp-const-max.ll?rev=221157&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/AArch64/cmp-const-max.ll (added)
+++ llvm/trunk/test/CodeGen/AArch64/cmp-const-max.ll Mon Nov  3 09:28:40 2014
@@ -0,0 +1,36 @@
+; RUN: llc -verify-machineinstrs -aarch64-atomic-cfg-tidy=0 < %s -mtriple=aarch64-none-eabihf -fast-isel=false | FileCheck %s
+
+
+define i32 @ule_64_max(i64 %p) {
+entry:
+; CHECK-LABEL: ule_64_max:
+; CHECK: cmn x0, #1
+; CHECK: b.hi [[RET_ZERO:.LBB[0-9]+_[0-9]+]]
+  %cmp = icmp ule i64 %p, 18446744073709551615 ; 0xffffffffffffffff
+  br i1 %cmp, label %ret_one, label %ret_zero
+
+ret_one:
+  ret i32 1
+
+ret_zero:
+; CHECK: [[RET_ZERO]]:
+; CHECK-NEXT: mov w0, wzr
+  ret i32 0
+}
+
+define i32 @ugt_64_max(i64 %p) {
+entry:
+; CHECK-LABEL: ugt_64_max:
+; CHECK: cmn x0, #1
+; CHECK: b.ls [[RET_ZERO:.LBB[0-9]+_[0-9]+]]
+  %cmp = icmp ugt i64 %p, 18446744073709551615 ; 0xffffffffffffffff
+  br i1 %cmp, label %ret_one, label %ret_zero
+
+ret_one:
+  ret i32 1
+
+ret_zero:
+; CHECK: [[RET_ZERO]]:
+; CHECK-NEXT: mov w0, wzr
+  ret i32 0
+}