[GlobalISel] Fix the select->minmax combine from trying to operate on pointer types.

Author: aemerson

llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp

@@ -6555,6 +6555,9 @@ bool CombinerHelper::tryFoldSelectToIntMinMax(GSelect *Select,
   Register False = Select->getFalseReg();
   LLT DstTy = MRI.getType(DstReg);
 
+  if (DstTy.isPointer())
+    return false;
+
   // We need an G_ICMP on the condition register.
   GICmp *Cmp = getOpcodeDef<GICmp>(Cond, MRI);
   if (!Cmp)

llvm/test/CodeGen/AArch64/GlobalISel/combine-select.mir

@@ -825,3 +825,30 @@ body:             |
     %sel:_(<4 x s32>) = exact G_SELECT %c, %t, %f
     $q0 = COPY %sel(<4 x s32>)
 ...
+---
+name:            dont_combine_pointer_type
+body:             |
+  bb.1:
+    liveins: $x0
+
+    ; CHECK-LABEL: name: dont_combine_pointer_type
+    ; CHECK: liveins: $x0
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: [[COPY:%[0-9]+]]:_(p0) = COPY $x0
+    ; CHECK-NEXT: [[C:%[0-9]+]]:_(p0) = G_CONSTANT i64 0
+    ; CHECK-NEXT: [[LOAD:%[0-9]+]]:_(p0) = G_LOAD [[C]](p0) :: (load (p0))
+    ; CHECK-NEXT: [[ICMP:%[0-9]+]]:_(s1) = G_ICMP intpred(ugt), [[LOAD]](p0), [[C]]
+    ; CHECK-NEXT: [[SELECT:%[0-9]+]]:_(p0) = G_SELECT [[ICMP]](s1), [[LOAD]], [[C]]
+    ; CHECK-NEXT: G_STORE [[SELECT]](p0), [[COPY]](p0) :: (store (p0))
+    ; CHECK-NEXT: $x0 = COPY [[C]](p0)
+    ; CHECK-NEXT: RET_ReallyLR implicit $x0
+    %0:_(p0) = COPY $x0
+    %2:_(p0) = G_CONSTANT i64 0
+    %1:_(p0) = G_LOAD %2(p0) :: (load (p0))
+    %3:_(s1) = G_ICMP intpred(ugt), %1(p0), %2
+    %4:_(p0) = G_SELECT %3(s1), %1, %2
+    G_STORE %4(p0), %0(p0) :: (store (p0))
+    $x0 = COPY %2(p0)
+    RET_ReallyLR implicit $x0
+
+...