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[compiler-rt] Make sure __clzdi2 doesn't call itself recursively on sparc64 (#136737)

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On 64-bit platforms, libgcc doesn't ship with __clzsi2, so __builtin_clz
gets lowered to __clzdi2. A check already exists for GCC, but as of
commit 8210ca0198 clang also lowers
__builtin_clz to __clzdi2 on sparc64.

Update the check so that building __clzdi2 with clang/sparc64 also
works.
This commit is contained in:
Koakuma
2025-04-29 07:36:32 +07:00
committed by GitHub
parent 4def437cdc
commit 5d0e26e571
1 changed files with 4 additions and 4 deletions
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8
compiler-rt/lib/builtins/clzdi2.c
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@@ -14,12 +14,12 @@
// Returns: the number of leading 0-bits
#if !defined(__clang__) && \
((defined(__sparc__) && defined(__arch64__)) || defined(__mips64) || \
#if ((defined(__sparc__) && defined(__arch64__)) || defined(__mips64) || \
(defined(__riscv) && __SIZEOF_POINTER__ >= 8))
// On 64-bit architectures with neither a native clz instruction nor a native
// ctz instruction, gcc resolves __builtin_clz to __clzdi2 rather than
// __clzsi2, leading to infinite recursion.
// ctz instruction, `__builtin_clz` resolves to `__clzdi2` rather than
// __clzsi2 as libgcc does not ship with `__clzsi2`, leading to infinite
// recursion.
#define __builtin_clz(a) __clzsi2(a)
extern int __clzsi2(si_int);
#endif