Re: [PATCH v1 08/11] perf annotate-data: Add invalidate_reg_state() helper for x86

[Namhyung Kim]

On Mon, Jan 26, 2026 at 09:05:01PM -0500, Zecheng Li wrote:
> Add a helper function to consistently invalidate register state instead
> of field assignments. This ensures kind, ok, and copied_from are all
> properly cleared when a register becomes invalid.
> 
> The helper sets:
> - kind = TSR_KIND_INVALID
> - ok = false
> - copied_from = -1
> 
> Replace all invalidation patterns with calls to this helper. No
> functional change and this removes some incorrect annotations that were
> caused by incomplete invalidation (e.g. a obsolete copied_from from an
> invalidated register).

It doesn't apply cleanly from here.  Please rebase onto the current
perf-tools-next.  Maybe we want to wait for v7.0-rc1.

Thanks,
Namhyung

> 
> Signed-off-by: Zecheng Li <zli94@xxxxxxxx>
> ---
>  tools/perf/arch/x86/annotate/instructions.c | 29 ++++++++++++---------
>  1 file changed, 17 insertions(+), 12 deletions(-)
> 
> diff --git a/tools/perf/arch/x86/annotate/instructions.c b/tools/perf/arch/x86/annotate/instructions.c
> index 803f9351a3fb..e033abb0667b 100644
> --- a/tools/perf/arch/x86/annotate/instructions.c
> +++ b/tools/perf/arch/x86/annotate/instructions.c
> @@ -209,6 +209,13 @@ static int x86__annotate_init(struct arch *arch, char *cpuid)
>  }
>  
>  #ifdef HAVE_LIBDW_SUPPORT
> +static void invalidate_reg_state(struct type_state_reg *reg)
> +{
> +	reg->kind = TSR_KIND_INVALID;
> +	reg->ok = false;
> +	reg->copied_from = -1;
> +}
> +
>  static void update_insn_state_x86(struct type_state *state,
>  				  struct data_loc_info *dloc, Dwarf_Die *cu_die,
>  				  struct disasm_line *dl)
> @@ -240,7 +247,7 @@ static void update_insn_state_x86(struct type_state *state,
>  		/* Otherwise invalidate caller-saved registers after call */
>  		for (unsigned i = 0; i < ARRAY_SIZE(state->regs); i++) {
>  			if (state->regs[i].caller_saved)
> -				state->regs[i].ok = false;
> +				invalidate_reg_state(&state->regs[i]);
>  		}
>  
>  		/* Update register with the return type (if any) */
> @@ -369,8 +376,7 @@ static void update_insn_state_x86(struct type_state *state,
>  		src_tsr = state->regs[sreg];
>  		tsr = &state->regs[dst->reg1];
>  
> -		tsr->copied_from = -1;
> -		tsr->ok = false;
> +		invalidate_reg_state(tsr);
>  
>  		/* Case 1: Based on stack pointer or frame pointer */
>  		if (sreg == fbreg || sreg == state->stack_reg) {
> @@ -438,8 +444,7 @@ static void update_insn_state_x86(struct type_state *state,
>  		    !strncmp(dl->ins.name, "inc", 3)  || !strncmp(dl->ins.name, "dec", 3)) {
>  			pr_debug_dtp("%s [%x] invalidate reg%d\n",
>  						dl->ins.name, insn_offset, dst->reg1);
> -			state->regs[dst->reg1].ok = false;
> -			state->regs[dst->reg1].copied_from = -1;
> +			invalidate_reg_state(&state->regs[dst->reg1]);
>  			return;
>  		}
>  
> @@ -501,7 +506,7 @@ static void update_insn_state_x86(struct type_state *state,
>  			if (!get_global_var_type(cu_die, dloc, ip, var_addr,
>  						 &offset, &type_die) ||
>  			    !die_get_member_type(&type_die, offset, &type_die)) {
> -				tsr->ok = false;
> +				invalidate_reg_state(tsr);
>  				return;
>  			}
>  
> @@ -529,7 +534,7 @@ static void update_insn_state_x86(struct type_state *state,
>  
>  		if (!has_reg_type(state, src->reg1) ||
>  		    !state->regs[src->reg1].ok) {
> -			tsr->ok = false;
> +			invalidate_reg_state(tsr);
>  			return;
>  		}
>  
> @@ -565,7 +570,7 @@ static void update_insn_state_x86(struct type_state *state,
>  
>  			stack = find_stack_state(state, offset);
>  			if (stack == NULL) {
> -				tsr->ok = false;
> +				invalidate_reg_state(tsr);
>  				return;
>  			} else if (!stack->compound) {
>  				tsr->type = stack->type;
> @@ -580,7 +585,7 @@ static void update_insn_state_x86(struct type_state *state,
>  				tsr->offset = 0;
>  				tsr->ok = true;
>  			} else {
> -				tsr->ok = false;
> +				invalidate_reg_state(tsr);
>  				return;
>  			}
>  
> @@ -633,7 +638,7 @@ static void update_insn_state_x86(struct type_state *state,
>  			if (!get_global_var_type(cu_die, dloc, ip, addr, &offset,
>  						 &type_die) ||
>  			    !die_get_member_type(&type_die, offset, &type_die)) {
> -				tsr->ok = false;
> +				invalidate_reg_state(tsr);
>  				return;
>  			}
>  
> @@ -684,7 +689,7 @@ static void update_insn_state_x86(struct type_state *state,
>  				}
>  				pr_debug_type_name(&tsr->type, tsr->kind);
>  			} else {
> -				tsr->ok = false;
> +				invalidate_reg_state(tsr);
>  			}
>  		}
>  		/* And then dereference the calculated pointer if it has one */
> @@ -726,7 +731,7 @@ static void update_insn_state_x86(struct type_state *state,
>  				}
>  			}
>  
> -			tsr->ok = false;
> +			invalidate_reg_state(tsr);
>  		}
>  	}
>  	/* Case 3. register to memory transfers */
> -- 
> 2.52.0
>