[LLVMbugs] [Bug 15009] New: Clang coerces char __attribute__((ext_vector_type(4))) to int32.

[bugzilla-daemon at llvm.org]

http://llvm.org/bugs/show_bug.cgi?id=15009

             Bug #: 15009
           Summary: Clang coerces char __attribute__((ext_vector_type(4)))
                    to int32.
           Product: clang
           Version: trunk
          Platform: PC
        OS/Version: All
            Status: NEW
          Severity: normal
          Priority: P
         Component: LLVM Codegen
        AssignedTo: unassignedclangbugs at nondot.org
        ReportedBy: mgottesman at apple.com
                CC: llvmbugs at cs.uiuc.edu
    Classification: Unclassified


Clang compiles the following c code:

-----
typedef char char4 __attribute__((ext_vector_type(4)));

char4 sub(char4 x, char4 y) {
  return x + y;
}
-----

to the following using 'clang -c test.c -emit-llvm -S -o test.ll':

-----
; ModuleID = 'test.c'
target datalayout =
"e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
target triple = "x86_64-apple-macosx10.8.0"

define i32 @sub(i32 %x.coerce, i32 %y.coerce) nounwind uwtable ssp {
entry:
  %retval = alloca <4 x i8>, align 4
  %x = alloca <4 x i8>, align 4
  %x.addr = alloca <4 x i8>, align 4
  %y = alloca <4 x i8>, align 4
  %y.addr = alloca <4 x i8>, align 4
  %0 = bitcast <4 x i8>* %x to i32*
  store i32 %x.coerce, i32* %0, align 1
  %x1 = load <4 x i8>* %x, align 4
  store <4 x i8> %x1, <4 x i8>* %x.addr, align 4
  %1 = bitcast <4 x i8>* %y to i32*
  store i32 %y.coerce, i32* %1, align 1
  %y2 = load <4 x i8>* %y, align 4
  store <4 x i8> %y2, <4 x i8>* %y.addr, align 4
  %2 = load <4 x i8>* %x.addr, align 4
  %3 = load <4 x i8>* %y.addr, align 4
  %add = add <4 x i8> %2, %3
  store <4 x i8> %add, <4 x i8>* %retval
  %4 = bitcast <4 x i8>* %retval to i32*
  %5 = load i32* %4, align 1
  ret i32 %5
}
-----

Is this correct? IMHO clang should not be doing such coercions, no?

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