[llvm] r213784 - [NVPTX] mul.wide generation works for any smaller integer source types, not just the next smaller power of two

[Tobias Grosser]

On 23/07/2014 20:46, Justin Holewinski wrote:
> Author: jholewinski
> Date: Wed Jul 23 13:46:03 2014
> New Revision: 213784
>
> URL: http://llvm.org/viewvc/llvm-project?rev=213784&view=rev
> Log:
> [NVPTX] mul.wide generation works for any smaller integer source types, not just the next smaller power of two
>
> Modified:
>      llvm/trunk/lib/Target/NVPTX/NVPTXISelLowering.cpp
>      llvm/trunk/test/CodeGen/NVPTX/mulwide.ll
>
> Modified: llvm/trunk/lib/Target/NVPTX/NVPTXISelLowering.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/NVPTX/NVPTXISelLowering.cpp?rev=213784&r1=213783&r2=213784&view=diff
> ==============================================================================
> --- llvm/trunk/lib/Target/NVPTX/NVPTXISelLowering.cpp (original)
> +++ llvm/trunk/lib/Target/NVPTX/NVPTXISelLowering.cpp Wed Jul 23 13:46:03 2014
> @@ -4053,13 +4053,13 @@ static bool IsMulWideOperandDemotable(SD
>     if (Op.getOpcode() == ISD::SIGN_EXTEND ||
>         Op.getOpcode() == ISD::SIGN_EXTEND_INREG) {
>       EVT OrigVT = Op.getOperand(0).getValueType();
> -    if (OrigVT.getSizeInBits() == OptSize) {
> +    if (OrigVT.getSizeInBits() <= OptSize) {
>         S = Signed;
>         return true;
>       }
>     } else if (Op.getOpcode() == ISD::ZERO_EXTEND) {
>       EVT OrigVT = Op.getOperand(0).getValueType();
> -    if (OrigVT.getSizeInBits() == OptSize) {
> +    if (OrigVT.getSizeInBits() <= OptSize) {
>         S = Unsigned;
>         return true;
>       }
>
> Modified: llvm/trunk/test/CodeGen/NVPTX/mulwide.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/NVPTX/mulwide.ll?rev=213784&r1=213783&r2=213784&view=diff
> ==============================================================================
> --- llvm/trunk/test/CodeGen/NVPTX/mulwide.ll (original)
> +++ llvm/trunk/test/CodeGen/NVPTX/mulwide.ll Wed Jul 23 13:46:03 2014
> @@ -23,6 +23,28 @@ define i32 @mulwideu16(i16 %a, i16 %b) {
>     ret i32 %val2
>   }
>
> +; OPT-LABEL: @mulwide8
> +; NOOPT-LABEL: @mulwide8
> +define i32 @mulwide8(i8 %a, i8 %b) {
> +; OPT: mul.wide.s16
> +; NOOPT: mul.lo.s32
> +  %val0 = sext i8 %a to i32
> +  %val1 = sext i8 %b to i32
> +  %val2 = mul i32 %val0, %val1
> +  ret i32 %val2
> +}
> +
> +; OPT-LABEL: @mulwideu8
> +; NOOPT-LABEL: @mulwideu8
> +define i32 @mulwideu8(i8 %a, i8 %b) {
> +; OPT: mul.wide.u16
> +; NOOPT: mul.lo.s32
> +  %val0 = zext i8 %a to i32
> +  %val1 = zext i8 %b to i32
> +  %val2 = mul i32 %val0, %val1
> +  ret i32 %val2
> +}

If it works for any integer size, would it make sense to test non power 
of two sizes?

Cheers,
Tobias