The test is old, but I guess nobody tried running it in a 32-bit Windows build before wasm got enabled by default recently in r343746.

I didn't try it on 32-bit Linux, but I assume it's more a 32-bit x86 thing rather than a Windows thing.


FAIL: LLVM :: CodeGen/WebAssembly/immediates.ll (12964 of 28256)
******************** TEST 'LLVM :: CodeGen/WebAssembly/immediates.ll' FAILED ********************
Script:
--
: 'RUN: at line 1';   C:\src\llvm.svn\build.32\bin\llc.EXE < C:\src\llvm.svn\test\CodeGen\WebAssembly\immediates.ll -asm-verbose=false -disable-wasm-fallthrough-return-opt -wasm-keep-registers | C:\src\llvm.svn\build.32\bin\FileCheck.EXE C:\src\llvm.svn\test\CodeGen\WebAssembly\immediates.ll
--
Exit Code: 1

Command Output (stdout):
--
$ ":" "RUN: at line 1"
$ "C:\src\llvm.svn\build.32\bin\llc.EXE" "-asm-verbose=false" "-disable-wasm-fallthrough-return-opt" "-wasm-keep-registers"
$ "C:\src\llvm.svn\build.32\bin\FileCheck.EXE" "C:\src\llvm.svn\test\CodeGen\WebAssembly\immediates.ll"
# command stderr:
C:\src\llvm.svn\test\CodeGen\WebAssembly\immediates.ll:229:15: error: CHECK-NEXT: expected string not found in input
; CHECK-NEXT: f64.const $push[[NUM:[0-9]+]]=, -nan:0x2bcdef0123456{{$}}
              ^
<stdin>:305:2: note: scanning from here
 f64.const $push0=, -nan:0xabcdef0123456
 ^

error: command failed with exit status: 1

--


It looks like the upper 2 in 0xFFF2BCDEF012345 gets lost somewhere.

r260968 mentions MC converting floating point operands and potentially causing NaNs to change bits. Perhaps it's more of that happening?