Handle cases where a register and one of its super-register are both marked as
defined on the same instruction. This fixes PR1767.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43699 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/LiveVariables.cpp b/lib/CodeGen/LiveVariables.cpp
index 57396b7..7e8965e 100644
--- a/lib/CodeGen/LiveVariables.cpp
+++ b/lib/CodeGen/LiveVariables.cpp
@@ -203,7 +203,7 @@
RegInfo->isSuperRegister(IncomingReg, Reg) &&
MO.isKill())
// A super-register kill already exists.
- return true;
+ Found = true;
}
}
@@ -357,7 +357,9 @@
} else if (PhysRegPartUse[Reg])
// Add implicit use / kill to last partial use.
addRegisterKilled(Reg, PhysRegPartUse[Reg], true);
- else
+ else if (LastRef != MI)
+ // Defined, but not used. However, watch out for cases where a super-reg
+ // is also defined on the same MI.
addRegisterDead(Reg, LastRef);
}
diff --git a/test/CodeGen/X86/2007-11-04-LiveVariablesBug.ll b/test/CodeGen/X86/2007-11-04-LiveVariablesBug.ll
new file mode 100644
index 0000000..7e41f36
--- /dev/null
+++ b/test/CodeGen/X86/2007-11-04-LiveVariablesBug.ll
@@ -0,0 +1,16 @@
+; RUN: llvm-as < %s | llc -mtriple=x86_64-unknown-linux-gnu
+; PR1767
+
+define void @xor_sse_2(i64 %bytes, i64* %p1, i64* %p2) {
+entry:
+ %p2_addr = alloca i64* ; <i64**> [#uses=2]
+ %lines = alloca i32 ; <i32*> [#uses=2]
+ store i64* %p2, i64** %p2_addr, align 8
+ %tmp1 = lshr i64 %bytes, 8 ; <i64> [#uses=1]
+ %tmp12 = trunc i64 %tmp1 to i32 ; <i32> [#uses=2]
+ store i32 %tmp12, i32* %lines, align 4
+ %tmp6 = call i64* asm sideeffect "foo",
+"=r,=*r,=*r,r,0,1,2,~{dirflag},~{fpsr},~{flags},~{memory}"( i64** %p2_addr,
+i32* %lines, i64 256, i64* %p1, i64* %p2, i32 %tmp12 ) ; <i64*> [#uses=0]
+ ret void
+}