String interpolation(floating %g) does not consist to C version

[kbkpbot]

Describe the bug

String interpolation of float precision( %g) should consist to it's C version.

Reproduction Steps

A format.v

module main
fn main() {
        a := 31.2400e+200
        println('31.2400e+200 8.0g[${a:8.0g}]')
        println('31.2400e+200 8.1g[${a:8.1g}]')
        println('31.2400e+200 8.2g[${a:8.2g}]')
        println('31.2400e+200 8.3g[${a:8.3g}]')
        println('31.2400e+200 8.4g[${a:8.4g}]')
}

result is :

31.2400e+200 8.0g[        ]
31.2400e+200 8.1g[3.1e+201]
31.2400e+200 8.2g[3.12e+201]
31.2400e+200 8.3g[3.124e+201]
31.2400e+200 8.4g[3.124e+201]

A format.c

#include <stdio.h>
void main() {
        double c = 31.2400e+200;
        printf("31.2400e+200 8.0g[%8.0g]\n",c);
        printf("31.2400e+200 8.1g[%8.1g]\n",c);
        printf("31.2400e+200 8.2g[%8.2g]\n",c);
        printf("31.2400e+200 8.3g[%8.3g]\n",c);
        printf("31.2400e+200 8.4g[%8.4g]\n",c);
}

result is :

31.2400e+200 8.0g[  3e+201]
31.2400e+200 8.1g[  3e+201]
31.2400e+200 8.2g[3.1e+201]
31.2400e+200 8.3g[3.12e+201]
31.2400e+200 8.4g[3.124e+201]

Expected Behavior

V version will generate same result to it's C version

Current Behavior

They are different.

Possible Solution

format process has some bug?

Additional Information/Context

No response

V version

V full version: V 0.4.8 7b8e059.0390c07

Environment details (OS name and version, etc.)

V full version: V 0.4.8 7b8e059.0390c07
OS: linux, Ubuntu 24.04.1 LTS
Processor: 8 cpus, 64bit, little endian, Intel(R) Core(TM) i7-9700 CPU @ 3.00GHz

getwd: /home/mars/v/format
vexe: /media/HD/github/kbkpbot/v/v
vexe mtime: 2024-10-04 14:33:40

vroot: OK, value: /media/HD/github/kbkpbot/v
VMODULES: OK, value: /home/mars/.vmodules
VTMP: OK, value: /tmp/v_1000

Git version: git version 2.43.0
Git vroot status: 0.4.8-42-g0a997d90 (3 commit(s) behind V master)
.git/config present: true

CC version: cc (Ubuntu 13.2.0-23ubuntu4) 13.2.0
thirdparty/tcc status: thirdparty-linux-amd64 0134e9b9

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[kbkpbot]

ss.v

fn main() {
        a := 1234.5600e+100

        println('1234.5600e+100 8.3g[${a:8.3g}]')
}

create a wrong result:

1234.5600e+100 8.3g[0.1235e+104]

This should be :

1234.5600e+100 8.3g[1.23e+103]