[compiler-rt] support QUAD with native long double (PR #77981)

[Sean Perry via llvm-commits]

https://github.com/perry-ca created https://github.com/llvm/llvm-project/pull/77981

Redo #77554 to solve build issue found in #77880.

>From 01b59de67ffda70b8c2c5c1ea54b43d8e9f2c686 Mon Sep 17 00:00:00 2001
From: Sean Perry <perry at ca.ibm.com>
Date: Fri, 12 Jan 2024 14:49:41 -0600
Subject: [PATCH] support QUAD with native long double

---
 compiler-rt/lib/builtins/divtc3.c    | 2 +-
 compiler-rt/lib/builtins/fp_lib.h    | 6 +++++-
 compiler-rt/lib/builtins/int_types.h | 8 ++++++--
 compiler-rt/lib/builtins/multc3.c    | 2 +-
 4 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/compiler-rt/lib/builtins/divtc3.c b/compiler-rt/lib/builtins/divtc3.c
index e970cef574b21d..099de5802daf0e 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_TF_MODE)
+#if defined(CRT_HAS_F128)
 
 // Returns: the quotient of (a + ib) / (c + id)
 
diff --git a/compiler-rt/lib/builtins/fp_lib.h b/compiler-rt/lib/builtins/fp_lib.h
index af406e760497a4..4fca0183e54817 100644
--- a/compiler-rt/lib/builtins/fp_lib.h
+++ b/compiler-rt/lib/builtins/fp_lib.h
@@ -92,7 +92,7 @@ static __inline void wideMultiply(rep_t a, rep_t b, rep_t *hi, rep_t *lo) {
 
 COMPILER_RT_ABI fp_t __adddf3(fp_t a, fp_t b);
 
-#elif defined QUAD_PRECISION
+#elif defined QUAD_PRECISION && defined(CRT_HAS_F128)
 #if defined(CRT_HAS_TF_MODE)
 typedef uint64_t half_rep_t;
 typedef __uint128_t rep_t;
@@ -188,6 +188,8 @@ static __inline void wideMultiply(rep_t a, rep_t b, rep_t *hi, rep_t *lo) {
 #undef Word_HiMask
 #undef Word_LoMask
 #undef Word_FullMask
+#else
+typedef long double fp_t;
 #endif // defined(CRT_HAS_TF_MODE)
 #else
 #error SINGLE_PRECISION, DOUBLE_PRECISION or QUAD_PRECISION must be defined.
@@ -405,6 +407,8 @@ static __inline tf_float __compiler_rt_fmaxtf(tf_float x, tf_float y) {
 #define __compiler_rt_logbl crt_logbl
 #define __compiler_rt_scalbnl crt_scalbnl
 #define __compiler_rt_fmaxl crt_fmaxl
+#define crt_fabstf crt_fabsl
+#define crt_copysigntf crt_copysignl
 #else
 #error Unsupported TF mode type
 #endif
diff --git a/compiler-rt/lib/builtins/int_types.h b/compiler-rt/lib/builtins/int_types.h
index 7624c728061518..219948850a97e5 100644
--- a/compiler-rt/lib/builtins/int_types.h
+++ b/compiler-rt/lib/builtins/int_types.h
@@ -189,12 +189,16 @@ typedef long double tf_float;
 #define CRT_LDBL_IEEE_F128
 #endif
 #define TF_C(x) x##L
-#elif __LDBL_MANT_DIG__ == 113
-// Use long double instead of __float128 if it matches the IEEE 128-bit format.
+#elif __LDBL_MANT_DIG__ == 113 ||
+    (__FLT_RADIX__ == 16 && __LDBL_MANT_DIG__ == 28)
+// Use long double instead of __float128 if it matches the IEEE 128-bit format
+// or the IBM hexadecimal format.
 #define CRT_LDBL_128BIT
 #define CRT_HAS_F128
+#if __LDBL_MANT_DIG__ == 113
 #define CRT_HAS_IEEE_TF
 #define CRT_LDBL_IEEE_F128
+#endif
 typedef long double tf_float;
 #define TF_C(x) x##L
 #elif defined(__FLOAT128__) || defined(__SIZEOF_FLOAT128__)
diff --git a/compiler-rt/lib/builtins/multc3.c b/compiler-rt/lib/builtins/multc3.c
index f20e53ccbf233b..61a3f45e47279c 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_TF_MODE)
+#if defined(CRT_HAS_F128)
 
 // Returns: the product of a + ib and c + id