[PATCH 1/2] libstdc++: case-sensitivity in hexfloat std::from_chars [PR105441]

[Patrick Palka via Gcc-patches]

The hexfloat parser for binary32/64 added in r12-6645-gcc3bf3404e4b1c
overlooked that the exponent part can also begin with an uppercase 'P'.

Tested on x86_64-pc-linux-gnu, does this look OK for trunk/11, and possibly the
12 branch now for 12.1?

PR libstdc++/105441

libstdc++-v3/ChangeLog:

* src/c++17/floating_from_chars.cc (__floating_from_chars_hex):
Also accept 'P' as the start of the exponent.
* testsuite/20_util/from_chars/7.cc: Add corresponding testcase.
---
 libstdc++-v3/src/c++17/floating_from_chars.cc  | 2 +-
 libstdc++-v3/testsuite/20_util/from_chars/7.cc | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/libstdc++-v3/src/c++17/floating_from_chars.cc 
b/libstdc++-v3/src/c++17/floating_from_chars.cc
index 13de1e346ab..e7f3a58cf18 100644
--- a/libstdc++-v3/src/c++17/floating_from_chars.cc
+++ b/libstdc++-v3/src/c++17/floating_from_chars.cc
@@ -664,7 +664,7 @@ namespace
 
 // Parse the written exponent.
 int written_exponent = 0;
-if (first != last && *first == 'p')
+if (first != last && (*first == 'p' || *first == 'P'))
   {
// Tentatively consume the 'p' and try to parse a decimal number.
const char* const fallback_first = first;
diff --git a/libstdc++-v3/testsuite/20_util/from_chars/7.cc 
b/libstdc++-v3/testsuite/20_util/from_chars/7.cc
index 2a78c7441e2..1aa9b230531 100644
--- a/libstdc++-v3/testsuite/20_util/from_chars/7.cc
+++ b/libstdc++-v3/testsuite/20_util/from_chars/7.cc
@@ -96,6 +96,7 @@ constexpr testcase testcases[] = {
   { "1p-1", 4, {}, 0x1p-1 },
   { "0", 1, {}, 0.0 },
   { "A", 1, {}, 0xA },
+  { "1.ABCDEFP+10", 12, {}, 0x1.ABCDEFP+10 },
   { "-1", 2, {}, -1.0 },
   { "-0", 2, {}, -0.0 },
   { "42", 2, {}, 0x42p0 },
-- 
2.36.0.44.g0f828332d5

Re: [PATCH 1/2] libstdc++: case-sensitivity in hexfloat std::from_chars [PR105441]

[Jonathan Wakely via Gcc-patches]

On Sun, 1 May 2022 at 19:22, Patrick Palka via Libstdc++
 wrote:
>
> The hexfloat parser for binary32/64 added in r12-6645-gcc3bf3404e4b1c
> overlooked that the exponent part can also begin with an uppercase 'P'.
>
> Tested on x86_64-pc-linux-gnu, does this look OK for trunk/11, and possibly 
> the
> 12 branch now for 12.1?

OK for trunk, and as it's a regression since gcc-11 I'd recommend
release manager approval for 12.1 as well, but it's the RMs call.



>
> PR libstdc++/105441
>
> libstdc++-v3/ChangeLog:
>
> * src/c++17/floating_from_chars.cc (__floating_from_chars_hex):
> Also accept 'P' as the start of the exponent.
> * testsuite/20_util/from_chars/7.cc: Add corresponding testcase.
> ---
>  libstdc++-v3/src/c++17/floating_from_chars.cc  | 2 +-
>  libstdc++-v3/testsuite/20_util/from_chars/7.cc | 1 +
>  2 files changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/libstdc++-v3/src/c++17/floating_from_chars.cc 
> b/libstdc++-v3/src/c++17/floating_from_chars.cc
> index 13de1e346ab..e7f3a58cf18 100644
> --- a/libstdc++-v3/src/c++17/floating_from_chars.cc
> +++ b/libstdc++-v3/src/c++17/floating_from_chars.cc
> @@ -664,7 +664,7 @@ namespace
>
>  // Parse the written exponent.
>  int written_exponent = 0;
> -if (first != last && *first == 'p')
> +if (first != last && (*first == 'p' || *first == 'P'))
>{
> // Tentatively consume the 'p' and try to parse a decimal number.
> const char* const fallback_first = first;
> diff --git a/libstdc++-v3/testsuite/20_util/from_chars/7.cc 
> b/libstdc++-v3/testsuite/20_util/from_chars/7.cc
> index 2a78c7441e2..1aa9b230531 100644
> --- a/libstdc++-v3/testsuite/20_util/from_chars/7.cc
> +++ b/libstdc++-v3/testsuite/20_util/from_chars/7.cc
> @@ -96,6 +96,7 @@ constexpr testcase testcases[] = {
>{ "1p-1", 4, {}, 0x1p-1 },
>{ "0", 1, {}, 0.0 },
>{ "A", 1, {}, 0xA },
> +  { "1.ABCDEFP+10", 12, {}, 0x1.ABCDEFP+10 },
>{ "-1", 2, {}, -1.0 },
>{ "-0", 2, {}, -0.0 },
>{ "42", 2, {}, 0x42p0 },
> --
> 2.36.0.44.g0f828332d5
>

Re: [PATCH 1/2] libstdc++: case-sensitivity in hexfloat std::from_chars [PR105441]

[Jakub Jelinek via Gcc-patches]

On Sun, May 01, 2022 at 08:09:05PM +0100, Jonathan Wakely via Gcc-patches wrote:
> On Sun, 1 May 2022 at 19:22, Patrick Palka via Libstdc++
>  wrote:
> >
> > The hexfloat parser for binary32/64 added in r12-6645-gcc3bf3404e4b1c
> > overlooked that the exponent part can also begin with an uppercase 'P'.
> >
> > Tested on x86_64-pc-linux-gnu, does this look OK for trunk/11, and possibly 
> > the
> > 12 branch now for 12.1?
> 
> OK for trunk, and as it's a regression since gcc-11 I'd recommend
> release manager approval for 12.1 as well, but it's the RMs call.

Ok for 12.1.

> > PR libstdc++/105441
> >
> > libstdc++-v3/ChangeLog:
> >
> > * src/c++17/floating_from_chars.cc (__floating_from_chars_hex):
> > Also accept 'P' as the start of the exponent.
> > * testsuite/20_util/from_chars/7.cc: Add corresponding testcase.

Jakub