From a1ad913da0cb85239309cae93b7a1bf83ad3e1e5 Mon Sep 17 00:00:00 2001
From: Richard Henderson <richard.henderson@linaro.org>
Date: Mon, 27 Feb 2023 11:33:20 -1000
Subject: [PATCH] target/arm: Simplify register counting in
 arm_gen_dynamic_svereg_xml
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Rather than increment base_reg and num, compute num from the change
to base_reg at the end.  Clean up some nearby comments.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20230227213329.793795-6-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 target/arm/gdbstub64.c | 27 ++++++++++++++++-----------
 1 file changed, 16 insertions(+), 11 deletions(-)

diff --git a/target/arm/gdbstub64.c b/target/arm/gdbstub64.c
index 811833d8de..070ba20d99 100644
--- a/target/arm/gdbstub64.c
+++ b/target/arm/gdbstub64.c
@@ -277,32 +277,35 @@ static void output_vector_union_type(GString *s, int reg_width)
     g_string_append(s, "</union>");
 }
 
-int arm_gen_dynamic_svereg_xml(CPUState *cs, int base_reg)
+int arm_gen_dynamic_svereg_xml(CPUState *cs, int orig_base_reg)
 {
     ARMCPU *cpu = ARM_CPU(cs);
     GString *s = g_string_new(NULL);
     DynamicGDBXMLInfo *info = &cpu->dyn_svereg_xml;
-    int i, reg_width = (cpu->sve_max_vq * 128);
-    info->num = 0;
+    int reg_width = cpu->sve_max_vq * 128;
+    int base_reg = orig_base_reg;
+    int i;
+
     g_string_printf(s, "<?xml version=\"1.0\"?>");
     g_string_append_printf(s, "<!DOCTYPE target SYSTEM \"gdb-target.dtd\">");
     g_string_append_printf(s, "<feature name=\"org.gnu.gdb.aarch64.sve\">");
 
+    /* Create the vector union type. */
     output_vector_union_type(s, reg_width);
 
-    /* Finally the sve prefix type */
+    /* Create the predicate vector type. */
     g_string_append_printf(s,
                            "<vector id=\"svep\" type=\"uint8\" count=\"%d\"/>",
                            reg_width / 8);
 
-    /* Then define each register in parts for each vq */
+    /* Define the vector registers. */
     for (i = 0; i < 32; i++) {
         g_string_append_printf(s,
                                "<reg name=\"z%d\" bitsize=\"%d\""
                                " regnum=\"%d\" type=\"svev\"/>",
                                i, reg_width, base_reg++);
-        info->num++;
     }
+
     /* fpscr & status registers */
     g_string_append_printf(s, "<reg name=\"fpsr\" bitsize=\"32\""
                            " regnum=\"%d\" group=\"float\""
@@ -310,27 +313,29 @@ int arm_gen_dynamic_svereg_xml(CPUState *cs, int base_reg)
     g_string_append_printf(s, "<reg name=\"fpcr\" bitsize=\"32\""
                            " regnum=\"%d\" group=\"float\""
                            " type=\"int\"/>", base_reg++);
-    info->num += 2;
 
+    /* Define the predicate registers. */
     for (i = 0; i < 16; i++) {
         g_string_append_printf(s,
                                "<reg name=\"p%d\" bitsize=\"%d\""
                                " regnum=\"%d\" type=\"svep\"/>",
                                i, cpu->sve_max_vq * 16, base_reg++);
-        info->num++;
     }
     g_string_append_printf(s,
                            "<reg name=\"ffr\" bitsize=\"%d\""
                            " regnum=\"%d\" group=\"vector\""
                            " type=\"svep\"/>",
                            cpu->sve_max_vq * 16, base_reg++);
+
+    /* Define the vector length pseudo-register. */
     g_string_append_printf(s,
                            "<reg name=\"vg\" bitsize=\"64\""
                            " regnum=\"%d\" type=\"int\"/>",
                            base_reg++);
-    info->num += 2;
-    g_string_append_printf(s, "</feature>");
-    info->desc = g_string_free(s, false);
 
+    g_string_append_printf(s, "</feature>");
+
+    info->desc = g_string_free(s, false);
+    info->num = base_reg - orig_base_reg;
     return info->num;
 }