CreateVirtualRegisters does trivial copy coalescing. If a node def is used by a single CopyToReg, it reuses the virtual register assigned to the CopyToReg. This won't work for SDNode that is a clone or is itself cloned. Disable this optimization for those nodes or it can end up with non-SSA machine instructions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62356 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 50 insertions, 0 deletions

diff --git a/test/CodeGen/X86/2009-01-16-SchedulerBug.ll b/test/CodeGen/X86/2009-01-16-SchedulerBug.ll
new file mode 100644
index 0000000000..ff20dc1e30
--- /dev/null
+++ b/test/CodeGen/X86/2009-01-16-SchedulerBug.ll
@@ -0,0 +1,50 @@
+; RUN: llvm-as < %s | llc -mtriple=i386-apple-darwin
+; rdar://6501631
+
+	%CF = type { %Register }
+	%XXV = type { i32 (...)** }
+	%Register = type { %"struct.XXC::BCFs", i32 }
+	%"struct.XXC::BCFs" = type { i32 }
+
+declare { i32, i1 } @llvm.sadd.with.overflow.i32(i32, i32) nounwind
+
+define fastcc %XXV* @bar(%CF* %call_frame, %XXV** %exception) nounwind {
+prologue:
+	%param_x = load %XXV** null		; <%XXV*> [#uses=1]
+	%unique_1.i = ptrtoint %XXV* %param_x to i1		; <i1> [#uses=1]
+	br i1 %unique_1.i, label %NextVerify42, label %FailedVerify
+
+NextVerify42:		; preds = %prologue
+	%param_y = load %XXV** null		; <%XXV*> [#uses=1]
+	%unique_1.i58 = ptrtoint %XXV* %param_y to i1		; <i1> [#uses=1]
+	br i1 %unique_1.i58, label %function_setup.cont, label %FailedVerify
+
+function_setup.cont:		; preds = %NextVerify42
+	br i1 false, label %label13, label %label
+
+label:		; preds = %function_setup.cont
+	%has_exn = icmp eq %XXV* null, null		; <i1> [#uses=1]
+	br i1 %has_exn, label %kjsNumberLiteral.exit, label %handle_exception
+
+kjsNumberLiteral.exit:		; preds = %label
+	%0 = call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 0, i32 0)		; <{ i32, i1 }> [#uses=2]
+	%intAdd = extractvalue { i32, i1 } %0, 0		; <i32> [#uses=2]
+	%intAddOverflow = extractvalue { i32, i1 } %0, 1		; <i1> [#uses=1]
+	%toint56 = ashr i32 %intAdd, 1		; <i32> [#uses=1]
+	%toFP57 = sitofp i32 %toint56 to double		; <double> [#uses=1]
+	br i1 %intAddOverflow, label %rematerializeAdd, label %label13
+
+label13:		; preds = %kjsNumberLiteral.exit, %function_setup.cont
+	%var_lr1.0 = phi double [ %toFP57, %kjsNumberLiteral.exit ], [ 0.000000e+00, %function_setup.cont ]		; <double> [#uses=0]
+	unreachable
+
+FailedVerify:		; preds = %NextVerify42, %prologue
+	ret %XXV* null
+
+rematerializeAdd:		; preds = %kjsNumberLiteral.exit
+	%rematerializedInt = sub i32 %intAdd, 0		; <i32> [#uses=0]
+	ret %XXV* null
+
+handle_exception:		; preds = %label
+	ret %XXV* undef
+}