[fast-isel] Don't try to encode LONG_MIN using cmn instructions.

rdar://11038907

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152847 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/ARM/ARMFastISel.cpp b/lib/Target/ARM/ARMFastISel.cpp
index 71de52fcaaa408cf7a8aec76160ca17b85fbd302..4651a3ac929edcac31dbc598c916278e8eaf2af5 100644 (file)
--- a/lib/Target/ARM/ARMFastISel.cpp
+++ b/lib/Target/ARM/ARMFastISel.cpp
@@ -1384,12 +1384,16 @@ bool ARMFastISel::ARMEmitCmp(const Value *Src1Value, const Value *Src2Value,
         SrcVT == MVT::i1) {
       const APInt &CIVal = ConstInt->getValue();
       Imm = (isZExt) ? (int)CIVal.getZExtValue() : (int)CIVal.getSExtValue();
-      if (Imm < 0) {
-        isNegativeImm = true;
-        Imm = -Imm;
+      // We can't encode LONG_MIN (i.e., 0x80000000) as an immediate because
+      // there is no way to represent 2147483648 as a signed 32-bit int.
+      if (Imm != (int)0x80000000) {
+        if (Imm < 0) {
+          isNegativeImm = true;
+          Imm = -Imm;
+        }
+        UseImm = isThumb2 ? (ARM_AM::getT2SOImmVal(Imm) != -1) :
+          (ARM_AM::getSOImmVal(Imm) != -1);
       }
-      UseImm = isThumb2 ? (ARM_AM::getT2SOImmVal(Imm) != -1) :
-        (ARM_AM::getSOImmVal(Imm) != -1);
     }
   } else if (const ConstantFP *ConstFP = dyn_cast<ConstantFP>(Src2Value)) {
     if (SrcVT == MVT::f32 || SrcVT == MVT::f64)