From: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Date: Tue, 30 Jan 2018 02:00:16 +0000 (+0100)
Subject: Re-add workaround for LLVM bug 11663
X-Git-Tag: archive/raspbian/1.30.0+dfsg1-2+rpi1~1^2~17
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=25b57db3de353f0338e34c404e0983a656c180ad;p=rustc.git

Re-add workaround for LLVM bug 11663


Gbp-Pq: Name u-compiler-rt.patch
---

diff --git a/src/libcompiler_builtins/compiler-rt/lib/builtins/int_lib.h b/src/libcompiler_builtins/compiler-rt/lib/builtins/int_lib.h
index 0b62666303..a286a87610 100644
--- a/src/libcompiler_builtins/compiler-rt/lib/builtins/int_lib.h
+++ b/src/libcompiler_builtins/compiler-rt/lib/builtins/int_lib.h
@@ -99,6 +99,28 @@ si_int __ctzsi2(si_int);
 #define	__builtin_ctz __ctzsi2
 #endif /* sparc64 || mips_n64 || mips_o64 || riscv */
 
+/*
+ * Workaround for LLVM bug 11663.  Prevent endless recursion in
+ * __c?zdi2(), where calls to __builtin_c?z() are expanded to
+ * __c?zdi2() instead of __c?zsi2().
+ *
+ * Instead of placing this workaround in c?zdi2.c, put it in this
+ * global header to prevent other C files from making the detour
+ * through __c?zdi2() as well.
+ *
+ * This problem has been observed on FreeBSD for sparc64 and
+ * mips64 with GCC 4.2.1, and for riscv with GCC 5.2.0.
+ * Presumably it's any version of GCC, and targeting an arch that
+ * does not have dedicated bit counting instructions.
+ */
+#if ((defined(__sparc__) && defined(__arch64__)) || defined(__mips_n64) || defined(__mips_o64) || defined(__riscv__) \
+		|| (defined(_MIPS_SIM) && ((_MIPS_SIM == _ABI64) || (_MIPS_SIM == _ABIO64))))
+si_int __clzsi2(si_int);
+si_int __ctzsi2(si_int);
+#define	__builtin_clz __clzsi2
+#define	__builtin_ctz __ctzsi2
+#endif /* sparc64 || mips_n64 || mips_o64 || riscv */
+
 COMPILER_RT_ABI si_int __paritysi2(si_int a);
 COMPILER_RT_ABI si_int __paritydi2(di_int a);