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authorDan Gohman <gohman@apple.com>2008-10-02 15:04:30 +0000
committerDan Gohman <gohman@apple.com>2008-10-02 15:04:30 +0000
commit0ce00b8a4f91d799029ffa4d63ef59987051db2e (patch)
tree0e9338969e8b60a7f9e22a317d7a6f1cdca5d6a4
parent833a77c3e36023fd3a250fc4eecb4e55024d1802 (diff)
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Fix a think-o in isSafeToMove. This fixes it from thinking that
volatile memory references are safe to move. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56948 91177308-0d34-0410-b5e6-96231b3b80d8
-rw-r--r--lib/CodeGen/MachineInstr.cpp2
-rw-r--r--test/CodeGen/X86/volatile.ll17
2 files changed, 18 insertions, 1 deletions
diff --git a/lib/CodeGen/MachineInstr.cpp b/lib/CodeGen/MachineInstr.cpp
index 4db02f4..4a7059a 100644
--- a/lib/CodeGen/MachineInstr.cpp
+++ b/lib/CodeGen/MachineInstr.cpp
@@ -707,7 +707,7 @@ bool MachineInstr::isSafeToMove(const TargetInstrInfo *TII, bool &SawStore) {
if (TID->mayLoad() && !TII->isInvariantLoad(this))
// Otherwise, this is a real load. If there is a store between the load and
// end of block, or if the laod is volatile, we can't move it.
- return SawStore || hasVolatileMemoryRef();
+ return !SawStore && !hasVolatileMemoryRef();
return true;
}
diff --git a/test/CodeGen/X86/volatile.ll b/test/CodeGen/X86/volatile.ll
new file mode 100644
index 0000000..e40f87b
--- /dev/null
+++ b/test/CodeGen/X86/volatile.ll
@@ -0,0 +1,17 @@
+; RUN: llvm-as < %s | llc -march=x86 -mattr=sse2 | grep movsd | count 5
+; RUN: llvm-as < %s | llc -march=x86 -mattr=sse2 -fast | grep movsd | count 5
+
+@x = external global double
+
+define void @foo() nounwind {
+ %a = volatile load double* @x
+ volatile store double 0.0, double* @x
+ volatile store double 0.0, double* @x
+ %b = volatile load double* @x
+ ret void
+}
+
+define void @bar() nounwind {
+ %c = volatile load double* @x
+ ret void
+}