Subzero: Fix x86 floating-point constant emission

tests_lit/llvm2ice_tests/fpconst.pnacl.ll

 ; This is a smoke test for floating-point constant pooling.  It tests
 ; pooling of various float and double constants (including positive
 ; and negative NaN) within functions and across functions.  Note that
 ; in LLVM bitcode, hex constants are used for an FP constant whenever
 ; the constant "cannot be represented as a decimal floating point
 ; number in a reasonable number of digits".  See
 ; http://llvm.org/docs/LangRef.html#simple-constants .
 
+; RUN: %llvm2ice -Om1 --verbose none %s | FileCheck %s
 ; RUN: %llvm2ice --verbose none %s | FileCheck --check-prefix=ERRORS %s
 ; RUN: %llvm2iceinsts %s | %szdiff %s | FileCheck --check-prefix=DUMP %s
 ; RUN: %llvm2iceinsts --pnacl %s | %szdiff %s \
 ; RUN:                           | FileCheck --check-prefix=DUMP %s
 
 @__init_array_start = internal constant [0 x i8] zeroinitializer, align 4
 @__fini_array_start = internal constant [0 x i8] zeroinitializer, align 4
 @__tls_template_start = internal constant [0 x i8] zeroinitializer, align 8
 @__tls_template_alignment = internal constant [4 x i8] c"\01\00\00\00", align 4
 
@@ skipping 508 matching lines @@
   %call66 = call float @Dummy(i32 -110)
   %conv67 = fpext float %call66 to double
   %add68 = fadd double %conv67, 0xFFF8000000000000
   br label %return
 
 return:                                           ; preds = %entry, %sw.bb65, %sw.bb61, %sw.bb57, %sw.bb53, %sw.bb49, %sw.bb45, %sw.bb41, %sw.bb37, %sw.bb33, %sw.bb29, %sw.bb25, %sw.bb21, %sw.bb17, %sw.bb13, %sw.bb9, %sw.bb5, %sw.bb1, %sw.bb
   %retval.0 = phi double [ %add68, %sw.bb65 ], [ %add64, %sw.bb61 ], [ %add60, %sw.bb57 ], [ %add56, %sw.bb53 ], [ %add52, %sw.bb49 ], [ %conv48, %sw.bb45 ], [ %conv44, %sw.bb41 ], [ %conv40, %sw.bb37 ], [ %conv36, %sw.bb33 ], [ %add32, %sw.bb29 ], [ %add28, %sw.bb25 ], [ %add24, %sw.bb21 ], [ %add20, %sw.bb17 ], [ %add16, %sw.bb13 ], [ %conv12, %sw.bb9 ], [ %conv8, %sw.bb5 ], [ %conv4, %sw.bb1 ], [ %conv, %sw.bb ], [ 0.000000e+00, %entry ]
   ret double %retval.0
 }
 
+; The FP constant pool entries for each type are dumped in some
+; implementation-dependent order.  So for the purposes of lit, we just
+; pick one value for each type, and make sure it appears exactly once.
+
+; Check for float 0.5
+; CHECK:     .long   0x3f000000
+; CHECK-NOT: .long   0x3f000000
+; Check for double 0.5
+; CHECK:     .quad   0x3fe0000000000000
+; CHECK-NOT: .quad   0x3fe0000000000000
+
 ; ERRORS-NOT: ICE translation error
 ; DUMP-NOT: SZ