[LLVMbugs] [Bug 8482] New: arm_neon.h contains wrong definition of vshl

[bugzilla-daemon at llvm.org]

http://llvm.org/bugs/show_bug.cgi?id=8482

           Summary: arm_neon.h contains wrong definition of vshl
           Product: clang
           Version: trunk
          Platform: PC
        OS/Version: Linux
            Status: NEW
          Severity: normal
          Priority: P
         Component: Headers
        AssignedTo: unassignedclangbugs at nondot.org
        ReportedBy: rengolin at gmail.com
                CC: llvmbugs at cs.uiuc.edu


Created an attachment (id=5676)
 --> (http://llvm.org/bugs/attachment.cgi?id=5676)
example

In Clang's arm_neon.h, the definitions of vshl_u* are wrong.

According to ARM's document [1], the shift amount parameter is
*always* signed, even for unsigned values, since a negative shift
means right shift.

I believe the header should be changed to conform to ARM's specification.

[1]
http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0491a/BABDFGBJ.html

Compile example:

$ clang -ccc-host-triple armv7a-none-eabi -ccc-gcc-name arm-none-eabi-gcc
-mfloat-abi=hard -w -emit-llvm -S vshl.c

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