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-rw-r--r--lib/CodeGen/MachineCSE.cpp7
-rw-r--r--test/CodeGen/X86/lsr-loop-exit-cond.ll4
-rw-r--r--test/CodeGen/X86/machine-cse.ll22
3 files changed, 29 insertions, 4 deletions
diff --git a/lib/CodeGen/MachineCSE.cpp b/lib/CodeGen/MachineCSE.cpp
index 5153abbc4e..993975ef0e 100644
--- a/lib/CodeGen/MachineCSE.cpp
+++ b/lib/CodeGen/MachineCSE.cpp
@@ -215,8 +215,11 @@ bool MachineCSE::hasLivePhysRegDefUses(const MachineInstr *MI,
if (MO.isDef() &&
(MO.isDead() || isPhysDefTriviallyDead(Reg, I, MBB->end())))
continue;
- for (MCRegAliasIterator AI(Reg, TRI, true); AI.isValid(); ++AI)
- PhysRefs.insert(*AI);
+ for (MCRegAliasIterator AI(Reg, TRI, true); AI.isValid(); ++AI) {
+ // Reading constant physregs is ok.
+ if (!MRI->isConstantPhysReg(*AI, *MBB->getParent()))
+ PhysRefs.insert(*AI);
+ }
if (MO.isDef())
PhysDefs.push_back(Reg);
}
diff --git a/test/CodeGen/X86/lsr-loop-exit-cond.ll b/test/CodeGen/X86/lsr-loop-exit-cond.ll
index 6e8d0bfdfe..8a81f70a8a 100644
--- a/test/CodeGen/X86/lsr-loop-exit-cond.ll
+++ b/test/CodeGen/X86/lsr-loop-exit-cond.ll
@@ -3,11 +3,11 @@
; CHECK: t:
; CHECK: decq
-; CHECK-NEXT: movl (%r11,%rax,4), %eax
+; CHECK-NEXT: movl (%r9,%rax,4), %eax
; CHECK-NEXT: jne
; ATOM: t:
-; ATOM: movl (%r10,%rax,4), %eax
+; ATOM: movl (%r9,%rax,4), %eax
; ATOM-NEXT: decq
; ATOM-NEXT: jne
diff --git a/test/CodeGen/X86/machine-cse.ll b/test/CodeGen/X86/machine-cse.ll
index 33bef70444..d171fd5f1d 100644
--- a/test/CodeGen/X86/machine-cse.ll
+++ b/test/CodeGen/X86/machine-cse.ll
@@ -134,3 +134,25 @@ return:
%retval.0 = phi i8* [ null, %entry ], [ null, %do.cond ], [ %p.0, %do.body ]
ret i8* %retval.0
}
+
+; PR13578
+@t2_global = external global i32
+
+declare i1 @t2_func()
+
+define i32 @t2() {
+ store i32 42, i32* @t2_global
+ %c = call i1 @t2_func()
+ br i1 %c, label %a, label %b
+
+a:
+ %l = load i32* @t2_global
+ ret i32 %l
+
+b:
+ ret i32 0
+
+; CHECK: t2:
+; CHECK: t2_global@GOTPCREL(%rip)
+; CHECK-NOT: t2_global@GOTPCREL(%rip)
+}