Stop creating extraneous smax/umax in SCEV. This removes a regression where we

started complicating many loops ('for' loops, in fact).

llvm-svn: 53508

3 files changed, 67 insertions, 1 deletions

diff --git a/llvm/test/Analysis/ScalarEvolution/2007-08-06-Unsigned.ll b/llvm/test/Analysis/ScalarEvolution/2007-08-06-Unsigned.ll
index 23ffc650b0d..e725852cea1 100644
--- a/llvm/test/Analysis/ScalarEvolution/2007-08-06-Unsigned.ll
+++ b/llvm/test/Analysis/ScalarEvolution/2007-08-06-Unsigned.ll
@@ -1,4 +1,4 @@
-; RUN: llvm-as < %s | opt -scalar-evolution -analyze | grep {Loop bb: ( -1 + ( -1 \\*  %x) + (( 1 +  %x) umax  %y)) iterations!}
+; RUN: llvm-as < %s | opt -scalar-evolution -analyze | grep {Loop bb: ( -1 + ( -1 \\*  %x) +  %y) iterations!}
 ; PR1597
 
 define i32 @f(i32 %x, i32 %y) {
diff --git a/llvm/test/Analysis/ScalarEvolution/2008-07-12-UnneededSelect1.ll b/llvm/test/Analysis/ScalarEvolution/2008-07-12-UnneededSelect1.ll
new file mode 100644
index 00000000000..a0fcad71314
--- /dev/null
+++ b/llvm/test/Analysis/ScalarEvolution/2008-07-12-UnneededSelect1.ll
@@ -0,0 +1,36 @@
+; RUN: llvm-as < %s | opt -analyze -scalar-evolution |& not grep smax
+; PR2261
+
+@lut = common global [256 x i8] zeroinitializer, align 32		; <[256 x i8]*> [#uses=1]
+
+define void @foo(i32 %count, i32* %srcptr, i32* %dstptr) nounwind  {
+entry:
+	icmp sgt i32 %count, 0		; <i1>:0 [#uses=1]
+	br i1 %0, label %bb.nph, label %return
+
+bb.nph:		; preds = %entry
+	br label %bb
+
+bb:		; preds = %bb1, %bb.nph
+	%j.01 = phi i32 [ %8, %bb1 ], [ 0, %bb.nph ]		; <i32> [#uses=1]
+	load i32* %srcptr, align 4		; <i32>:1 [#uses=2]
+	and i32 %1, 255		; <i32>:2 [#uses=1]
+	and i32 %1, -256		; <i32>:3 [#uses=1]
+	getelementptr [256 x i8]* @lut, i32 0, i32 %2		; <i8*>:4 [#uses=1]
+	load i8* %4, align 1		; <i8>:5 [#uses=1]
+	zext i8 %5 to i32		; <i32>:6 [#uses=1]
+	or i32 %6, %3		; <i32>:7 [#uses=1]
+	store i32 %7, i32* %dstptr, align 4
+	add i32 %j.01, 1		; <i32>:8 [#uses=2]
+	br label %bb1
+
+bb1:		; preds = %bb
+	icmp slt i32 %8, %count		; <i1>:9 [#uses=1]
+	br i1 %9, label %bb, label %bb1.return_crit_edge
+
+bb1.return_crit_edge:		; preds = %bb1
+	br label %return
+
+return:		; preds = %bb1.return_crit_edge, %entry
+	ret void
+}
diff --git a/llvm/test/Analysis/ScalarEvolution/2008-07-12-UnneededSelect2.ll b/llvm/test/Analysis/ScalarEvolution/2008-07-12-UnneededSelect2.ll
new file mode 100644
index 00000000000..5501ee28869
--- /dev/null
+++ b/llvm/test/Analysis/ScalarEvolution/2008-07-12-UnneededSelect2.ll
@@ -0,0 +1,30 @@
+; RUN: llvm-as < %s | opt -analyze -scalar-evolution |& not grep smax
+; PR2070
+
+define i32 @a(i32 %x) nounwind  {
+entry:
+	icmp sgt i32 %x, 1		; <i1>:0 [#uses=1]
+	br i1 %0, label %bb.nph, label %bb2
+
+bb.nph:		; preds = %entry
+	br label %bb
+
+bb:		; preds = %bb1, %bb.nph
+	%z.02 = phi i32 [ %1, %bb1 ], [ 1, %bb.nph ]		; <i32> [#uses=1]
+	%i.01 = phi i32 [ %2, %bb1 ], [ 1, %bb.nph ]		; <i32> [#uses=2]
+	mul i32 %z.02, %i.01		; <i32>:1 [#uses=2]
+	add i32 %i.01, 1		; <i32>:2 [#uses=2]
+	br label %bb1
+
+bb1:		; preds = %bb
+	icmp slt i32 %2, %x		; <i1>:3 [#uses=1]
+	br i1 %3, label %bb, label %bb1.bb2_crit_edge
+
+bb1.bb2_crit_edge:		; preds = %bb1
+	%.lcssa = phi i32 [ %1, %bb1 ]		; <i32> [#uses=1]
+	br label %bb2
+
+bb2:		; preds = %bb1.bb2_crit_edge, %entry
+	%z.0.lcssa = phi i32 [ %.lcssa, %bb1.bb2_crit_edge ], [ 1, %entry ]		; <i32> [#uses=1]
+	ret i32 %z.0.lcssa
+}