Generalize LSR's OptimizeSMax to handle unsigned max tests as well

as signed max tests. Along with r73717, this helps CodeGen avoid
emitting code for a maximum operation for this class of loop.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73718 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 78 insertions, 0 deletions

diff --git a/test/CodeGen/X86/optimize-max-1.ll b/test/CodeGen/X86/optimize-max-1.ll
new file mode 100644
index 0000000000..084e1818f5
--- /dev/null
+++ b/test/CodeGen/X86/optimize-max-1.ll
@@ -0,0 +1,78 @@
+; RUN: llvm-as < %s | llc -march=x86-64 | not grep cmov
+
+; LSR should be able to eliminate both smax and umax expressions
+; in loop trip counts.
+
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128"
+
+define void @fs(double* nocapture %p, i64 %n) nounwind {
+entry:
+	%tmp = icmp slt i64 %n, 1		; <i1> [#uses=1]
+	%smax = select i1 %tmp, i64 1, i64 %n		; <i64> [#uses=1]
+	br label %bb
+
+bb:		; preds = %bb, %entry
+	%i.0 = phi i64 [ 0, %entry ], [ %0, %bb ]		; <i64> [#uses=2]
+	%scevgep = getelementptr double* %p, i64 %i.0		; <double*> [#uses=1]
+	store double 0.000000e+00, double* %scevgep, align 8
+	%0 = add i64 %i.0, 1		; <i64> [#uses=2]
+	%exitcond = icmp eq i64 %0, %smax		; <i1> [#uses=1]
+	br i1 %exitcond, label %return, label %bb
+
+return:		; preds = %bb
+	ret void
+}
+
+define void @bs(double* nocapture %p, i64 %n) nounwind {
+entry:
+	%tmp = icmp sge i64 %n, 1		; <i1> [#uses=1]
+	%smax = select i1 %tmp, i64 %n, i64 1		; <i64> [#uses=1]
+	br label %bb
+
+bb:		; preds = %bb, %entry
+	%i.0 = phi i64 [ 0, %entry ], [ %0, %bb ]		; <i64> [#uses=2]
+	%scevgep = getelementptr double* %p, i64 %i.0		; <double*> [#uses=1]
+	store double 0.000000e+00, double* %scevgep, align 8
+	%0 = add i64 %i.0, 1		; <i64> [#uses=2]
+	%exitcond = icmp eq i64 %0, %smax		; <i1> [#uses=1]
+	br i1 %exitcond, label %return, label %bb
+
+return:		; preds = %bb
+	ret void
+}
+
+define void @fu(double* nocapture %p, i64 %n) nounwind {
+entry:
+	%tmp = icmp eq i64 %n, 0		; <i1> [#uses=1]
+	%umax = select i1 %tmp, i64 1, i64 %n		; <i64> [#uses=1]
+	br label %bb
+
+bb:		; preds = %bb, %entry
+	%i.0 = phi i64 [ 0, %entry ], [ %0, %bb ]		; <i64> [#uses=2]
+	%scevgep = getelementptr double* %p, i64 %i.0		; <double*> [#uses=1]
+	store double 0.000000e+00, double* %scevgep, align 8
+	%0 = add i64 %i.0, 1		; <i64> [#uses=2]
+	%exitcond = icmp eq i64 %0, %umax		; <i1> [#uses=1]
+	br i1 %exitcond, label %return, label %bb
+
+return:		; preds = %bb
+	ret void
+}
+
+define void @bu(double* nocapture %p, i64 %n) nounwind {
+entry:
+	%tmp = icmp ne i64 %n, 0		; <i1> [#uses=1]
+	%umax = select i1 %tmp, i64 %n, i64 1		; <i64> [#uses=1]
+	br label %bb
+
+bb:		; preds = %bb, %entry
+	%i.0 = phi i64 [ 0, %entry ], [ %0, %bb ]		; <i64> [#uses=2]
+	%scevgep = getelementptr double* %p, i64 %i.0		; <double*> [#uses=1]
+	store double 0.000000e+00, double* %scevgep, align 8
+	%0 = add i64 %i.0, 1		; <i64> [#uses=2]
+	%exitcond = icmp eq i64 %0, %umax		; <i1> [#uses=1]
+	br i1 %exitcond, label %return, label %bb
+
+return:		; preds = %bb
+	ret void
+}