[llvm-branch-commits] [compiler-rt] release/19.x: [builtins] Fix divtc3.c etc. compilation on Solaris/SPARC with gcc (#101662) (PR #101847)

[via llvm-branch-commits]

https://github.com/llvmbot created https://github.com/llvm/llvm-project/pull/101847

Backport 63a7786111c501920afc4cc27a4633f76cdaf803

Requested by: @rorth

>From 8773b58bdbb60fb6c1ae51dff7f8e6e9b221a183 Mon Sep 17 00:00:00 2001
From: Rainer Orth <ro at gcc.gnu.org>
Date: Sat, 3 Aug 2024 22:18:11 +0200
Subject: [PATCH] [builtins] Fix divtc3.c etc. compilation on Solaris/SPARC
 with gcc (#101662)
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`compiler-rt/lib/builtins/divtc3.c` and `multc3.c` don't compile on
Solaris/sparcv9 with `gcc -m32`:
```
FAILED: projects/compiler-rt/lib/builtins/CMakeFiles/clang_rt.builtins-sparc.dir/divtc3.c.o
[...]
compiler-rt/lib/builtins/divtc3.c: In function ‘__divtc3’:
compiler-rt/lib/builtins/divtc3.c:22:18: error: implicit declaration of function ‘__compiler_rt_logbtf’ [-Wimplicit-function-declaration]
   22 |   fp_t __logbw = __compiler_rt_logbtf(
      |                  ^~~~~~~~~~~~~~~~~~~~
```
and many more. It turns out that while the definition of `__divtc3` is
guarded with `CRT_HAS_F128`, the `__compiler_rt_logbtf` and other
declarations use `CRT_HAS_128BIT && CRT_HAS_F128` as guard. This only
shows up with `gcc` since, as documented in Issue #41838, `clang`
violates the SPARC psABI in not using 128-bit `long double`, so this
code path isn't used.

Fixed by changing the guards to match.

Tested on `sparcv9-sun-solaris2.11`.

(cherry picked from commit 63a7786111c501920afc4cc27a4633f76cdaf803)
---
 compiler-rt/lib/builtins/divtc3.c | 2 +-
 compiler-rt/lib/builtins/multc3.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/compiler-rt/lib/builtins/divtc3.c b/compiler-rt/lib/builtins/divtc3.c
index 099de5802daf0..c393de815337e 100644
--- a/compiler-rt/lib/builtins/divtc3.c
+++ b/compiler-rt/lib/builtins/divtc3.c
@@ -13,7 +13,7 @@
 #define QUAD_PRECISION
 #include "fp_lib.h"
 
-#if defined(CRT_HAS_F128)
+#if defined(CRT_HAS_128BIT) && defined(CRT_HAS_F128)
 
 // Returns: the quotient of (a + ib) / (c + id)
 
diff --git a/compiler-rt/lib/builtins/multc3.c b/compiler-rt/lib/builtins/multc3.c
index 61a3f45e47279..a89832f0e883e 100644
--- a/compiler-rt/lib/builtins/multc3.c
+++ b/compiler-rt/lib/builtins/multc3.c
@@ -15,7 +15,7 @@
 #include "int_lib.h"
 #include "int_math.h"
 
-#if defined(CRT_HAS_F128)
+#if defined(CRT_HAS_128BIT) && defined(CRT_HAS_F128)
 
 // Returns: the product of a + ib and c + id