ef78c305fa
- Generate atomicrmw operations in most of the cases when it's sensible to do so. - Don't crash in several common cases (and hopefully don't crash in more of them). - Add some better tests. We now generate significantly better code for things like: _Atomic(int) x; ... x++; On MIPS, this now generates a 4-instruction ll/sc loop, where previously it generated about 30 instructions in two nested loops. On x86-64, we generate a single lock incl, instead of a lock cmpxchgl loop (one instruction instead of ten). llvm-svn: 176420
19 lines
361 B
C
19 lines
361 B
C
// RUN: %clang_cc1 -emit-llvm %s -o - | FileCheck %s
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void foo(int x)
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{
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_Atomic(int) i = 0;
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_Atomic(short) j = 0;
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// Check that multiply / divides on atomics produce a cmpxchg loop
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i *= 2;
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// CHECK: mul nsw i32
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// CHECK: cmpxchg i32*
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i /= 2;
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// CHECK: sdiv i32
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// CHECK: cmpxchg i32*
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j /= x;
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// CHECK: sdiv i32
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// CHECK: cmpxchg i16*
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}
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