[InstCombine] move and add tests for icmp + shl nsw; NFC

As discussed here:
http://lists.llvm.org/pipermail/llvm-dev/2017-January/108749.html
...we should be able to better optimize this pattern.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291262 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/test/Transforms/InstCombine/icmp-shl-nsw.ll b/test/Transforms/InstCombine/icmp-shl-nsw.ll
new file mode 100644 (file)
index 0000000..85e397e
--- /dev/null
+++ b/test/Transforms/InstCombine/icmp-shl-nsw.ll
@@ -0,0 +1,205 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -instcombine -S | FileCheck %s
+
+; If the (shl x, C) preserved the sign and this is a sign test,
+; compare the LHS operand instead
+
+define i1 @icmp_shl_nsw_sgt(i32 %x) {
+; CHECK-LABEL: @icmp_shl_nsw_sgt(
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i32 %x, 0
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %shl = shl nsw i32 %x, 21
+  %cmp = icmp sgt i32 %shl, 0
+  ret i1 %cmp
+}
+
+define i1 @icmp_shl_nsw_sge0(i32 %x) {
+; CHECK-LABEL: @icmp_shl_nsw_sge0(
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i32 %x, -1
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %shl = shl nsw i32 %x, 21
+  %cmp = icmp sge i32 %shl, 0
+  ret i1 %cmp
+}
+
+define i1 @icmp_shl_nsw_sge1(i32 %x) {
+; CHECK-LABEL: @icmp_shl_nsw_sge1(
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i32 %x, 0
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %shl = shl nsw i32 %x, 21
+  %cmp = icmp sge i32 %shl, 1
+  ret i1 %cmp
+}
+
+define <2 x i1> @icmp_shl_nsw_sge1_vec(<2 x i32> %x) {
+; CHECK-LABEL: @icmp_shl_nsw_sge1_vec(
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt <2 x i32> %x, zeroinitializer
+; CHECK-NEXT:    ret <2 x i1> [[CMP]]
+;
+  %shl = shl nsw <2 x i32> %x, <i32 21, i32 21>
+  %cmp = icmp sge <2 x i32> %shl, <i32 1, i32 1>
+  ret <2 x i1> %cmp
+}
+
+; Checks for icmp (eq|ne) (shl x, C), 0
+
+define i1 @icmp_shl_nsw_eq(i32 %x) {
+; CHECK-LABEL: @icmp_shl_nsw_eq(
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i32 %x, 0
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %mul = shl nsw i32 %x, 5
+  %cmp = icmp eq i32 %mul, 0
+  ret i1 %cmp
+}
+
+define <2 x i1> @icmp_shl_nsw_eq_vec(<2 x i32> %x) {
+; CHECK-LABEL: @icmp_shl_nsw_eq_vec(
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq <2 x i32> %x, zeroinitializer
+; CHECK-NEXT:    ret <2 x i1> [[CMP]]
+;
+  %mul = shl nsw <2 x i32> %x, <i32 5, i32 5>
+  %cmp = icmp eq <2 x i32> %mul, zeroinitializer
+  ret <2 x i1> %cmp
+}
+
+; icmp sgt with shl nsw with a constant compare operand and constant
+; shift amount can always be reduced to icmp sgt alone.
+
+; Known bits analysis turns this into an equality predicate.
+
+define i1 @icmp_sgt1(i8 %x) {
+; CHECK-LABEL: @icmp_sgt1(
+; CHECK-NEXT:    [[SHL_MASK:%.*]] = and i8 %x, 127
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ne i8 [[SHL_MASK]], 64
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %shl = shl nsw i8 %x, 1
+  %cmp = icmp sgt i8 %shl, -128
+  ret i1 %cmp
+}
+
+define i1 @icmp_sgt2(i8 %x) {
+; CHECK-LABEL: @icmp_sgt2(
+; CHECK-NEXT:    [[SHL:%.*]] = shl nsw i8 %x, 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i8 [[SHL]], -127
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %shl = shl nsw i8 %x, 1
+  %cmp = icmp sgt i8 %shl, -127
+  ret i1 %cmp
+}
+
+define i1 @icmp_sgt3(i8 %x) {
+; CHECK-LABEL: @icmp_sgt3(
+; CHECK-NEXT:    [[SHL:%.*]] = shl nsw i8 %x, 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i8 [[SHL]], -16
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %shl = shl nsw i8 %x, 1
+  %cmp = icmp sgt i8 %shl, -16
+  ret i1 %cmp
+}
+
+define i1 @icmp_sgt4(i8 %x) {
+; CHECK-LABEL: @icmp_sgt4(
+; CHECK-NEXT:    [[SHL:%.*]] = shl nsw i8 %x, 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i8 [[SHL]], -2
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %shl = shl nsw i8 %x, 1
+  %cmp = icmp sgt i8 %shl, -2
+  ret i1 %cmp
+}
+
+; x >s -1 is a sign bit test.
+; x >s 0 is a sign bit test.
+
+define i1 @icmp_sgt5(i8 %x) {
+; CHECK-LABEL: @icmp_sgt5(
+; CHECK-NEXT:    [[SHL:%.*]] = shl nsw i8 %x, 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i8 [[SHL]], 1
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %shl = shl nsw i8 %x, 1
+  %cmp = icmp sgt i8 %shl, 1
+  ret i1 %cmp
+}
+
+define i1 @icmp_sgt6(i8 %x) {
+; CHECK-LABEL: @icmp_sgt6(
+; CHECK-NEXT:    [[SHL:%.*]] = shl nsw i8 %x, 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i8 [[SHL]], 16
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %shl = shl nsw i8 %x, 1
+  %cmp = icmp sgt i8 %shl, 16
+  ret i1 %cmp
+}
+
+define i1 @icmp_sgt7(i8 %x) {
+; CHECK-LABEL: @icmp_sgt7(
+; CHECK-NEXT:    [[SHL:%.*]] = shl nsw i8 %x, 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i8 [[SHL]], 124
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %shl = shl nsw i8 %x, 1
+  %cmp = icmp sgt i8 %shl, 124
+  ret i1 %cmp
+}
+
+; Known bits analysis turns this into an equality predicate.
+
+define i1 @icmp_sgt8(i8 %x) {
+; CHECK-LABEL: @icmp_sgt8(
+; CHECK-NEXT:    [[SHL_MASK:%.*]] = and i8 %x, 127
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i8 [[SHL_MASK]], 63
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %shl = shl nsw i8 %x, 1
+  %cmp = icmp sgt i8 %shl, 125
+  ret i1 %cmp
+}
+
+; Compares with 126 and 127 are recognized as always false.
+
+; Known bits analysis turns this into an equality predicate.
+
+define i1 @icmp_sgt9(i8 %x) {
+; CHECK-LABEL: @icmp_sgt9(
+; CHECK-NEXT:    [[SHL_MASK:%.*]] = and i8 %x, 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i8 [[SHL_MASK]], 0
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %shl = shl nsw i8 %x, 7
+  %cmp = icmp sgt i8 %shl, -128
+  ret i1 %cmp
+}
+
+define i1 @icmp_sgt10(i8 %x) {
+; CHECK-LABEL: @icmp_sgt10(
+; CHECK-NEXT:    [[SHL:%.*]] = shl nsw i8 %x, 7
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i8 [[SHL]], -127
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %shl = shl nsw i8 %x, 7
+  %cmp = icmp sgt i8 %shl, -127
+  ret i1 %cmp
+}
+
+define i1 @icmp_sgt11(i8 %x) {
+; CHECK-LABEL: @icmp_sgt11(
+; CHECK-NEXT:    [[SHL:%.*]] = shl nsw i8 %x, 7
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i8 [[SHL]], -2
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %shl = shl nsw i8 %x, 7
+  %cmp = icmp sgt i8 %shl, -2
+  ret i1 %cmp
+}
+
+; Known bits analysis returns false for compares with >=0.
+

diff --git a/test/Transforms/InstCombine/icmp.ll b/test/Transforms/InstCombine/icmp.ll
index 099aaca5f7d6ea4be21943bddeb4be9d1b7697fc..32fe050bf83f0fd09d3490a13e5149c774ca579f 100644 (file)
--- a/test/Transforms/InstCombine/icmp.ll
+++ b/test/Transforms/InstCombine/icmp.ll
@@ -1243,69 +1243,6 @@ define i1 @icmp_shl24(i32 %x) {
   ret i1 %cmp
 }
 
-; If the (shl x, C) preserved the sign and this is a sign test,
-; compare the LHS operand instead
-define i1 @icmp_shl_nsw_sgt(i32 %x) {
-; CHECK-LABEL: @icmp_shl_nsw_sgt(
-; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i32 %x, 0
-; CHECK-NEXT:    ret i1 [[CMP]]
-;
-  %shl = shl nsw i32 %x, 21
-  %cmp = icmp sgt i32 %shl, 0
-  ret i1 %cmp
-}
-
-define i1 @icmp_shl_nsw_sge0(i32 %x) {
-; CHECK-LABEL: @icmp_shl_nsw_sge0(
-; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i32 %x, -1
-; CHECK-NEXT:    ret i1 [[CMP]]
-;
-  %shl = shl nsw i32 %x, 21
-  %cmp = icmp sge i32 %shl, 0
-  ret i1 %cmp
-}
-
-define i1 @icmp_shl_nsw_sge1(i32 %x) {
-; CHECK-LABEL: @icmp_shl_nsw_sge1(
-; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i32 %x, 0
-; CHECK-NEXT:    ret i1 [[CMP]]
-;
-  %shl = shl nsw i32 %x, 21
-  %cmp = icmp sge i32 %shl, 1
-  ret i1 %cmp
-}
-
-define <2 x i1> @icmp_shl_nsw_sge1_vec(<2 x i32> %x) {
-; CHECK-LABEL: @icmp_shl_nsw_sge1_vec(
-; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt <2 x i32> %x, zeroinitializer
-; CHECK-NEXT:    ret <2 x i1> [[CMP]]
-;
-  %shl = shl nsw <2 x i32> %x, <i32 21, i32 21>
-  %cmp = icmp sge <2 x i32> %shl, <i32 1, i32 1>
-  ret <2 x i1> %cmp
-}
-
-; Checks for icmp (eq|ne) (shl x, C), 0
-define i1 @icmp_shl_nsw_eq(i32 %x) {
-; CHECK-LABEL: @icmp_shl_nsw_eq(
-; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i32 %x, 0
-; CHECK-NEXT:    ret i1 [[CMP]]
-;
-  %mul = shl nsw i32 %x, 5
-  %cmp = icmp eq i32 %mul, 0
-  ret i1 %cmp
-}
-
-define <2 x i1> @icmp_shl_nsw_eq_vec(<2 x i32> %x) {
-; CHECK-LABEL: @icmp_shl_nsw_eq_vec(
-; CHECK-NEXT:    [[CMP:%.*]] = icmp eq <2 x i32> %x, zeroinitializer
-; CHECK-NEXT:    ret <2 x i1> [[CMP]]
-;
-  %mul = shl nsw <2 x i32> %x, <i32 5, i32 5>
-  %cmp = icmp eq <2 x i32> %mul, zeroinitializer
-  ret <2 x i1> %cmp
-}
-
 define i1 @icmp_shl_eq(i32 %x) {
 ; CHECK-LABEL: @icmp_shl_eq(
 ; CHECK-NEXT:    [[MUL_MASK:%.*]] = and i32 %x, 134217727