Bitcast of 64-bit immediates may need to split the immediate, not a var.

tests_lit/llvm2ice_tests/bitcast.ll

Index: tests_lit/llvm2ice_tests/bitcast.ll
diff --git a/tests_lit/llvm2ice_tests/bitcast.ll b/tests_lit/llvm2ice_tests/bitcast.ll
index cab2e4344ae7e24a57cfdcca0dbf00999614da14..0361ae7cd3b7cb2055285d482d8a876ee2390847 100644
--- a/tests_lit/llvm2ice_tests/bitcast.ll
+++ b/tests_lit/llvm2ice_tests/bitcast.ll
@@ -11,7 +11,7 @@ entry:
   %v0 = bitcast float %f to i32
   ret i32 %v0
 }
-
+; CHECK-LABEL: cast_f2i
 ; CHECK: mov eax
 ; CHECK: ret
 
@@ -20,7 +20,7 @@ entry:
   %v0 = bitcast i32 %i to float
   ret float %v0
 }
-
+; CHECK-LABEL: cast_i2f
 ; CHECK: fld dword ptr
 ; CHECK: ret
 
@@ -29,7 +29,17 @@ entry:
   %v0 = bitcast double %d to i64
   ret i64 %v0
 }
+; CHECK-LABEL: cast_d2ll
+; CHECK: mov edx
+; CHECK: ret
 
+define internal i64 @cast_d2ll_const() {
+entry:
+  %v0 = bitcast double 0x12345678901234 to i64
+  ret i64 %v0
+}
+; CHECK-LABEL: cast_d2ll_const
+; CHECK: movsd xmm{{.*}}, {{.*}}L$double
 ; CHECK: mov edx
 ; CHECK: ret
 
@@ -38,7 +48,18 @@ entry:
   %v0 = bitcast i64 %ll to double
   ret double %v0
 }
+; CHECK-LABEL: cast_ll2d
+; CHECK: fld qword ptr
+; CHECK: ret
 
+define internal double @cast_ll2d_const() {
+entry:
+  %v0 = bitcast i64 12345678901234 to double
+  ret double %v0
+}
+; CHECK-LABEL: cast_ll2d_const
+; CHECK: mov {{.*}}, 1942892530
+; CHECK: mov {{.*}}, 2874
 ; CHECK: fld qword ptr
 ; CHECK: ret