cmd/compile: add opcode flag hasSideEffects for do-not-remove
Added a flag to generic and various architectures' atomic
operations that are judged to have observable side effects
and thus cannot be dead-code-eliminated.
Test requires GOMAXPROCS > 1 without preemption in loop.
Fixes #19182.
Change-Id: Id2230031abd2cca0bbb32fd68fc8a58fb912070f
Reviewed-on: https://go-review.googlesource.com/37333
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
diff --git a/src/cmd/compile/internal/ssa/gen/genericOps.go b/src/cmd/compile/internal/ssa/gen/genericOps.go
index f39598e..3854a39 100644
--- a/src/cmd/compile/internal/ssa/gen/genericOps.go
+++ b/src/cmd/compile/internal/ssa/gen/genericOps.go
@@ -441,20 +441,20 @@
// Atomic loads return a new memory so that the loads are properly ordered
// with respect to other loads and stores.
// TODO: use for sync/atomic at some point.
- {name: "AtomicLoad32", argLength: 2, typ: "(UInt32,Mem)"}, // Load from arg0. arg1=memory. Returns loaded value and new memory.
- {name: "AtomicLoad64", argLength: 2, typ: "(UInt64,Mem)"}, // Load from arg0. arg1=memory. Returns loaded value and new memory.
- {name: "AtomicLoadPtr", argLength: 2, typ: "(BytePtr,Mem)"}, // Load from arg0. arg1=memory. Returns loaded value and new memory.
- {name: "AtomicStore32", argLength: 3, typ: "Mem"}, // Store arg1 to *arg0. arg2=memory. Returns memory.
- {name: "AtomicStore64", argLength: 3, typ: "Mem"}, // Store arg1 to *arg0. arg2=memory. Returns memory.
- {name: "AtomicStorePtrNoWB", argLength: 3, typ: "Mem"}, // Store arg1 to *arg0. arg2=memory. Returns memory.
- {name: "AtomicExchange32", argLength: 3, typ: "(UInt32,Mem)"}, // Store arg1 to *arg0. arg2=memory. Returns old contents of *arg0 and new memory.
- {name: "AtomicExchange64", argLength: 3, typ: "(UInt64,Mem)"}, // Store arg1 to *arg0. arg2=memory. Returns old contents of *arg0 and new memory.
- {name: "AtomicAdd32", argLength: 3, typ: "(UInt32,Mem)"}, // Do *arg0 += arg1. arg2=memory. Returns sum and new memory.
- {name: "AtomicAdd64", argLength: 3, typ: "(UInt64,Mem)"}, // Do *arg0 += arg1. arg2=memory. Returns sum and new memory.
- {name: "AtomicCompareAndSwap32", argLength: 4, typ: "(Bool,Mem)"}, // if *arg0==arg1, then set *arg0=arg2. Returns true iff store happens and new memory.
- {name: "AtomicCompareAndSwap64", argLength: 4, typ: "(Bool,Mem)"}, // if *arg0==arg1, then set *arg0=arg2. Returns true iff store happens and new memory.
- {name: "AtomicAnd8", argLength: 3, typ: "Mem"}, // *arg0 &= arg1. arg2=memory. Returns memory.
- {name: "AtomicOr8", argLength: 3, typ: "Mem"}, // *arg0 |= arg1. arg2=memory. Returns memory.
+ {name: "AtomicLoad32", argLength: 2, typ: "(UInt32,Mem)"}, // Load from arg0. arg1=memory. Returns loaded value and new memory.
+ {name: "AtomicLoad64", argLength: 2, typ: "(UInt64,Mem)"}, // Load from arg0. arg1=memory. Returns loaded value and new memory.
+ {name: "AtomicLoadPtr", argLength: 2, typ: "(BytePtr,Mem)"}, // Load from arg0. arg1=memory. Returns loaded value and new memory.
+ {name: "AtomicStore32", argLength: 3, typ: "Mem", hasSideEffects: true}, // Store arg1 to *arg0. arg2=memory. Returns memory.
+ {name: "AtomicStore64", argLength: 3, typ: "Mem", hasSideEffects: true}, // Store arg1 to *arg0. arg2=memory. Returns memory.
+ {name: "AtomicStorePtrNoWB", argLength: 3, typ: "Mem", hasSideEffects: true}, // Store arg1 to *arg0. arg2=memory. Returns memory.
+ {name: "AtomicExchange32", argLength: 3, typ: "(UInt32,Mem)", hasSideEffects: true}, // Store arg1 to *arg0. arg2=memory. Returns old contents of *arg0 and new memory.
+ {name: "AtomicExchange64", argLength: 3, typ: "(UInt64,Mem)", hasSideEffects: true}, // Store arg1 to *arg0. arg2=memory. Returns old contents of *arg0 and new memory.
+ {name: "AtomicAdd32", argLength: 3, typ: "(UInt32,Mem)", hasSideEffects: true}, // Do *arg0 += arg1. arg2=memory. Returns sum and new memory.
+ {name: "AtomicAdd64", argLength: 3, typ: "(UInt64,Mem)", hasSideEffects: true}, // Do *arg0 += arg1. arg2=memory. Returns sum and new memory.
+ {name: "AtomicCompareAndSwap32", argLength: 4, typ: "(Bool,Mem)", hasSideEffects: true}, // if *arg0==arg1, then set *arg0=arg2. Returns true iff store happens and new memory.
+ {name: "AtomicCompareAndSwap64", argLength: 4, typ: "(Bool,Mem)", hasSideEffects: true}, // if *arg0==arg1, then set *arg0=arg2. Returns true iff store happens and new memory.
+ {name: "AtomicAnd8", argLength: 3, typ: "Mem", hasSideEffects: true}, // *arg0 &= arg1. arg2=memory. Returns memory.
+ {name: "AtomicOr8", argLength: 3, typ: "Mem", hasSideEffects: true}, // *arg0 |= arg1. arg2=memory. Returns memory.
}
// kind control successors implicit exit
