[Valgrind-developers] [valgrind] Fix operand / result types of Iop_DivU128[E], Iop_ModU128 and their signed counterparts

[Florian K. <fk...@so...>]

https://sourceware.org/cgit/valgrind/commit/?id=644d68e9501dd5679194dd5c8e0d3ce24764a1d8

commit 644d68e9501dd5679194dd5c8e0d3ce24764a1d8
Author: Florian Krohm <fl...@ei...>
Date:   Wed Jul 9 20:15:46 2025 +0000

    Fix operand / result 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.

Diff:
---
 VEX/priv/ir_defs.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/VEX/priv/ir_defs.c b/VEX/priv/ir_defs.c
index 9e7fbf920e..ba61758d74 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: