On Tue, Apr 21, 2020 at 10:39 AM H. Peter Anvin <hpa@xxxxxxxxx> wrote: > x32 is not x86-32. In Linux we generally call the latter "i386". Agreed. Most of the previous patches to this file use "x32" and this one just wanted to be consistent. > C7 /0 imm32 is a valid instruction on i386. However, it is also > inefficient when the destination is a register, because B8+r imm32 is > equivalent, and when the value is zero, XOR is indeed more efficient. > > The real error is using EMIT3() instead of EMIT2_off32(), but XOR is > more efficient. However, let's make the bug statement *correct*, or it > is going to confuse the Hades out of people in the future. I don't see how the bug statement is incorrect, which merely points out that "C7 C0 0" is an invalid instruction, regardless of whether the JIT intended to emit C7 /0 imm32, B8+r imm32, 31 /r, 33 /r, or any other equivalent form.
