[Valgrind-developers] typeOfPrimop fixes

[Florian K. <fl...@ei...>]

What are the operand types of Iop_DivU128[E], Iop_ModU128 and their signed 
counterparts?

In libvex_ir.h these IROps are described to operate on Ity_I128 operands and 
produce a like typed result. This contradicts the specification in ir_defs.c
function typeOfprimop which claims Ity_V128 for operands and result.

Above IROps are used exclusively by ppc for the following opcodes:
Iop_DivU128  --> vdivuq  Vector Divide Unsigned Quadword
Iop_DivS128  --> vdivsq  Vector Divide Signed Quadword
Iop_DivU128E --> vdiveuq Vector Divide Extended Unsigned Quadword
Iop_DivS128E --> vdivesq Vector Divide Extended Signed Quadword
Iop_ModU128  --> vmoduq  Vector Modulo Unsigned Quadword
Iop_ModS128  --> vmodsq  Vector Modulo Signed Quadword

Reading the ISA document, it is clear, that those opcodes perform an
integer division / modulo operation. Technically, they work on vector
registers, presumably because vector registers are the only resource
wide enough to store a quadword. Perhaps that is where the confusion
comes from.
So Ity_I128 it is.

Below patch regtested on ppc with no new failures.

OK?

diff --git a/VEX/priv/ir_defs.c b/VEX/priv/ir_defs.c
index 9e7fbf9..ba61758 100644
--- a/VEX/priv/ir_defs.c
+++ b/VEX/priv/ir_defs.c
@@ -3694,10 +3694,12 @@ void typeOfPrimop ( IROp op,
        case Iop_MulI128by10E:
        case Iop_MulI128by10ECarry:
        case Iop_PwExtUSMulQAdd8x16:
-      case Iop_DivU128: case Iop_DivS128:
+         BINARY(Ity_V128,Ity_V128, Ity_V128);
+
+      case Iop_DivU128:  case Iop_DivS128:
        case Iop_DivU128E: case Iop_DivS128E:
        case Iop_ModU128:  case Iop_ModS128:
-         BINARY(Ity_V128,Ity_V128, Ity_V128);
+         BINARY(Ity_I128,Ity_I128, Ity_I128);

        case Iop_2xMultU64Add128CarryOut:
        case Iop_Perm8x16x2: