From a33701098936ffba12326d96e98d388357f3e098 Mon Sep 17 00:00:00 2001
From: Duncan Sands <baldrick@free.fr>
Date: Tue, 8 May 2012 12:16:05 +0000
Subject: Calling ReassociateExpression recursively is extremely dangerous
 since it will replace the operands of expressions with only one use with
 undef and generate a new expression for the original without using RAUW to
 update the original. Thus any copies of the original expression held in a
 vector may end up referring to some bogus value - and using a ValueHandle
 won't help since there is no RAUW.  There is already a mechanism for getting
 the effect of recursion non-recursively: adding the value to be recursed on
 to RedoInsts.  But it wasn't being used systematically.  Have various places
 where recursion had snuck in at some point use the RedoInsts mechanism
 instead.  Fixes PR12169.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156379 91177308-0d34-0410-b5e6-96231b3b80d8
---
 .../Transforms/Reassociate/2012-05-08-UndefLeak.ll | 79 ++++++++++++++++++++++
 test/Transforms/Reassociate/multistep.ll           | 31 +++++++++
 2 files changed, 110 insertions(+)
 create mode 100644 test/Transforms/Reassociate/2012-05-08-UndefLeak.ll
 create mode 100644 test/Transforms/Reassociate/multistep.ll

(limited to 'test/Transforms/Reassociate')

diff --git a/test/Transforms/Reassociate/2012-05-08-UndefLeak.ll b/test/Transforms/Reassociate/2012-05-08-UndefLeak.ll
new file mode 100644
index 0000000000..8019361569
--- /dev/null
+++ b/test/Transforms/Reassociate/2012-05-08-UndefLeak.ll
@@ -0,0 +1,79 @@
+; RUN: opt < %s -reassociate -S | FileCheck %s
+; PR12169
+
+define i64 @f(i64 %x0) {
+; CHECK-NOT: undef
+  %t0 = add i64 %x0, 1
+  %t1 = add i64 %x0, 2
+  %t2 = add i64 %x0, 3
+  %t3 = add i64 %x0, 4
+  %t4 = add i64 %x0, 5
+  %t5 = add i64 %x0, 6
+  %t6 = add i64 %x0, 7
+  %t7 = add i64 %x0, 8
+  %t8 = add i64 %x0, 9
+  %t9 = add i64 %x0, 10
+  %t10 = add i64 %x0, 11
+  %t11 = add i64 %x0, 12
+  %t12 = add i64 %x0, 13
+  %t13 = add i64 %x0, 14
+  %t14 = add i64 %x0, 15
+  %t15 = add i64 %x0, 16
+  %t16 = add i64 %x0, 17
+  %t17 = add i64 %x0, 18
+  %t18 = add i64 %t17, %t0
+  %t19 = add i64 %t18, %t1
+  %t20 = add i64 %t19, %t2
+  %t21 = add i64 %t20, %t3
+  %t22 = add i64 %t21, %t4
+  %t23 = add i64 %t22, %t5
+  %t24 = add i64 %t23, %t6
+  %t25 = add i64 %t24, %t7
+  %t26 = add i64 %t25, %t8
+  %t27 = add i64 %t26, %t9
+  %t28 = add i64 %t27, %t10
+  %t29 = add i64 %t28, %t11
+  %t30 = add i64 %t29, %t12
+  %t31 = add i64 %t30, %t13
+  %t32 = add i64 %t31, %t14
+  %t33 = add i64 %t32, %t15
+  %t34 = add i64 %t33, %t16
+  %t35 = add i64 %t34, %x0
+  %t36 = add i64 %t0, %t1
+  %t37 = add i64 %t36, %t2
+  %t38 = add i64 %t37, %t3
+  %t39 = add i64 %t38, %t4
+  %t40 = add i64 %t39, %t5
+  %t41 = add i64 %t40, %t6
+  %t42 = add i64 %t41, %t7
+  %t43 = add i64 %t42, %t8
+  %t44 = add i64 %t43, %t9
+  %t45 = add i64 %t44, %t10
+  %t46 = add i64 %t45, %t11
+  %t47 = add i64 %t46, %t12
+  %t48 = add i64 %t47, %t13
+  %t49 = add i64 %t48, %t14
+  %t50 = add i64 %t49, %t15
+  %t51 = add i64 %t50, %t16
+  %t52 = add i64 %t51, %t17
+  %t53 = add i64 %t52, %t18
+  %t54 = add i64 %t53, %t19
+  %t55 = add i64 %t54, %t20
+  %t56 = add i64 %t55, %t21
+  %t57 = add i64 %t56, %t22
+  %t58 = add i64 %t57, %t23
+  %t59 = add i64 %t58, %t24
+  %t60 = add i64 %t59, %t25
+  %t61 = add i64 %t60, %t26
+  %t62 = add i64 %t61, %t27
+  %t63 = add i64 %t62, %t28
+  %t64 = add i64 %t63, %t29
+  %t65 = add i64 %t64, %t30
+  %t66 = add i64 %t65, %t31
+  %t67 = add i64 %t66, %t32
+  %t68 = add i64 %t67, %t33
+  %t69 = add i64 %t68, %t34
+  %t70 = add i64 %t69, %t35
+  %t71 = add i64 %t70, %x0
+  ret i64 %t71
+}
diff --git a/test/Transforms/Reassociate/multistep.ll b/test/Transforms/Reassociate/multistep.ll
new file mode 100644
index 0000000000..7466d2e99d
--- /dev/null
+++ b/test/Transforms/Reassociate/multistep.ll
@@ -0,0 +1,31 @@
+; RUN: opt < %s -reassociate -S | FileCheck %s
+
+define i64 @multistep1(i64 %a, i64 %b, i64 %c) {
+; Check that a*a*b+a*a*c is turned into a*(a*(b+c)).
+; CHECK: @multistep1
+  %t0 = mul i64 %a, %b
+  %t1 = mul i64 %a, %t0 ; a*(a*b)
+  %t2 = mul i64 %a, %c
+  %t3 = mul i64 %a, %t2 ; a*(a*c)
+  %t4 = add i64 %t1, %t3
+; CHECK-NEXT: add i64 %c, %b
+; CHECK-NEXT: mul i64 %tmp{{.*}}, %a
+; CHECK-NEXT: mul i64 %tmp{{.*}}, %a
+; CHECK-NEXT: ret
+  ret i64 %t4
+}
+
+define i64 @multistep2(i64 %a, i64 %b, i64 %c, i64 %d) {
+; Check that a*b+a*c+d is turned into a*(b+c)+d.
+; CHECK: @multistep2
+  %t0 = mul i64 %a, %b
+  %t1 = mul i64 %a, %c
+  %t2 = add i64 %t1, %d ; a*c+d
+  %t3 = add i64 %t0, %t2 ; a*b+(a*c+d)
+; CHECK-NEXT: add i64 %c, %b
+; CHECK-NEXT: mul i64 %tmp{{.*}}, %a
+; CHECK-NEXT: add i64 %tmp{{.*}}, %d
+; CHECK-NEXT: ret
+  ret i64 %t3
+}
+
-- 
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