From: Roman Lebedev <lebedev.ri@gmail.com>
Date: Mon, 1 Jul 2019 18:11:32 +0000 (+0000)
Subject: [NFC][InstCombine] Add tests for "shift direction in bittest" (PR42466)
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=6b0bb33c86a43c662ff7939d9042ee8f29acd59e;p=llvm

[NFC][InstCombine] Add tests for "shift direction in bittest" (PR42466)

https://rise4fun.com/Alive/8O1
https://bugs.llvm.org/show_bug.cgi?id=42466

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@364824 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/test/Transforms/InstCombine/shift-direction-in-bit-test.ll b/test/Transforms/InstCombine/shift-direction-in-bit-test.ll
new file mode 100644
index 00000000000..e9d5828888e
--- /dev/null
+++ b/test/Transforms/InstCombine/shift-direction-in-bit-test.ll
@@ -0,0 +1,234 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt %s -instcombine -S | FileCheck %s
+
+; The pattern:
+;   icmp eq/ne (and (X shift Y), Z), 0
+; is equivalent to pattern
+;   icmp eq/ne (and (Z oppositeshift Y), X), 0
+; We should canonicalize to one of them.
+; Let's go with 'lshr'.
+; Exception: unless it's a shift of constant, then don't touch it.
+
+;------------------------------------------------------------------------------;
+; Basic scalar test
+;------------------------------------------------------------------------------;
+
+define i1 @t0(i32 %x, i32 %y, i32 %z) {
+; CHECK-LABEL: @t0(
+; CHECK-NEXT:    [[T0:%.*]] = shl i32 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    [[T1:%.*]] = and i32 [[T0]], [[Z:%.*]]
+; CHECK-NEXT:    [[T2:%.*]] = icmp eq i32 [[T1]], 0
+; CHECK-NEXT:    ret i1 [[T2]]
+;
+  %t0 = shl i32 %x, %y
+  %t1 = and i32 %t0, %z
+  %t2 = icmp eq i32 %t1, 0
+  ret i1 %t2
+}
+
+define i1 @t1_ne(i32 %x, i32 %y, i32 %z) {
+; CHECK-LABEL: @t1_ne(
+; CHECK-NEXT:    [[T0:%.*]] = shl i32 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    [[T1:%.*]] = and i32 [[T0]], [[Z:%.*]]
+; CHECK-NEXT:    [[T2:%.*]] = icmp ne i32 [[T1]], 0
+; CHECK-NEXT:    ret i1 [[T2]]
+;
+  %t0 = shl i32 %x, %y
+  %t1 = and i32 %t0, %z
+  %t2 = icmp ne i32 %t1, 0
+  ret i1 %t2
+}
+
+;------------------------------------------------------------------------------;
+; Basic vector test
+;------------------------------------------------------------------------------;
+
+define <4 x i1> @t2_vec_splat(<4 x i32> %x, <4 x i32> %y, <4 x i32> %z) {
+; CHECK-LABEL: @t2_vec_splat(
+; CHECK-NEXT:    [[T0:%.*]] = shl <4 x i32> [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    [[T1:%.*]] = and <4 x i32> [[T0]], [[Z:%.*]]
+; CHECK-NEXT:    [[T2:%.*]] = icmp eq <4 x i32> [[T1]], zeroinitializer
+; CHECK-NEXT:    ret <4 x i1> [[T2]]
+;
+  %t0 = shl <4 x i32> %x, %y
+  %t1 = and <4 x i32> %t0, %z
+  %t2 = icmp eq <4 x i32> %t1, <i32 0, i32 0, i32 0, i32 0>
+  ret <4 x i1> %t2
+}
+
+define <4 x i1> @t3_vec_splat_undef(<4 x i32> %x, <4 x i32> %y, <4 x i32> %z) {
+; CHECK-LABEL: @t3_vec_splat_undef(
+; CHECK-NEXT:    [[T0:%.*]] = shl <4 x i32> [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    [[T1:%.*]] = and <4 x i32> [[T0]], [[Z:%.*]]
+; CHECK-NEXT:    [[T2:%.*]] = icmp eq <4 x i32> [[T1]], <i32 0, i32 0, i32 undef, i32 0>
+; CHECK-NEXT:    ret <4 x i1> [[T2]]
+;
+  %t0 = shl <4 x i32> %x, %y
+  %t1 = and <4 x i32> %t0, %z
+  %t2 = icmp eq <4 x i32> %t1, <i32 0, i32 0, i32 undef, i32 0>
+  ret <4 x i1> %t2
+}
+
+;------------------------------------------------------------------------------;
+; Commutativity
+;------------------------------------------------------------------------------;
+
+declare i32 @gen32()
+
+define i1 @t4_commutative(i32 %x, i32 %y) {
+; CHECK-LABEL: @t4_commutative(
+; CHECK-NEXT:    [[Z:%.*]] = call i32 @gen32()
+; CHECK-NEXT:    [[T0:%.*]] = shl i32 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    [[T1:%.*]] = and i32 [[Z]], [[T0]]
+; CHECK-NEXT:    [[T2:%.*]] = icmp eq i32 [[T1]], 0
+; CHECK-NEXT:    ret i1 [[T2]]
+;
+  %z = call i32 @gen32()
+  %t0 = shl i32 %x, %y
+  %t1 = and i32 %z, %t0 ; swapped
+  %t2 = icmp eq i32 %t1, 0
+  ret i1 %t2
+}
+
+;------------------------------------------------------------------------------;
+; Shifts in both hands of 'and'
+;------------------------------------------------------------------------------;
+
+define i1 @t5_twoshifts0(i32 %a, i32 %b, i32 %c, i32 %d) {
+; CHECK-LABEL: @t5_twoshifts0(
+; CHECK-NEXT:    [[T0:%.*]] = shl i32 [[A:%.*]], [[B:%.*]]
+; CHECK-NEXT:    [[T1:%.*]] = shl i32 [[T0]], [[C:%.*]]
+; CHECK-NEXT:    [[T2:%.*]] = and i32 [[T1]], [[D:%.*]]
+; CHECK-NEXT:    [[T3:%.*]] = icmp eq i32 [[T2]], 0
+; CHECK-NEXT:    ret i1 [[T3]]
+;
+  %t0 = shl i32 %a, %b
+  %t1 = shl i32 %t0, %c
+  %t2 = and i32 %t1, %d
+  %t3 = icmp eq i32 %t2, 0
+  ret i1 %t3
+}
+
+;------------------------------------------------------------------------------;
+; Extra uses
+;------------------------------------------------------------------------------;
+
+declare void @use32(i32)
+
+define i1 @t5_extrause0(i32 %x, i32 %y, i32 %z) {
+; CHECK-LABEL: @t5_extrause0(
+; CHECK-NEXT:    [[T0:%.*]] = shl i32 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    call void @use32(i32 [[T0]])
+; CHECK-NEXT:    [[T1:%.*]] = and i32 [[T0]], [[Z:%.*]]
+; CHECK-NEXT:    [[T2:%.*]] = icmp eq i32 [[T1]], 0
+; CHECK-NEXT:    ret i1 [[T2]]
+;
+  %t0 = shl i32 %x, %y
+  call void @use32(i32 %t0)
+  %t1 = and i32 %t0, %z
+  %t2 = icmp eq i32 %t1, 0
+  ret i1 %t2
+}
+
+define i1 @t6_extrause1(i32 %x, i32 %y, i32 %z) {
+; CHECK-LABEL: @t6_extrause1(
+; CHECK-NEXT:    [[T0:%.*]] = shl i32 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    [[T1:%.*]] = and i32 [[T0]], [[Z:%.*]]
+; CHECK-NEXT:    call void @use32(i32 [[T1]])
+; CHECK-NEXT:    [[T2:%.*]] = icmp eq i32 [[T1]], 0
+; CHECK-NEXT:    ret i1 [[T2]]
+;
+  %t0 = shl i32 %x, %y
+  %t1 = and i32 %t0, %z
+  call void @use32(i32 %t1)
+  %t2 = icmp eq i32 %t1, 0
+  ret i1 %t2
+}
+
+define i1 @t7_extrause2(i32 %x, i32 %y, i32 %z) {
+; CHECK-LABEL: @t7_extrause2(
+; CHECK-NEXT:    [[T0:%.*]] = shl i32 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    call void @use32(i32 [[T0]])
+; CHECK-NEXT:    [[T1:%.*]] = and i32 [[T0]], [[Z:%.*]]
+; CHECK-NEXT:    call void @use32(i32 [[T1]])
+; CHECK-NEXT:    [[T2:%.*]] = icmp eq i32 [[T1]], 0
+; CHECK-NEXT:    ret i1 [[T2]]
+;
+  %t0 = shl i32 %x, %y
+  call void @use32(i32 %t0)
+  %t1 = and i32 %t0, %z
+  call void @use32(i32 %t1)
+  %t2 = icmp eq i32 %t1, 0
+  ret i1 %t2
+}
+
+;------------------------------------------------------------------------------;
+; Constants
+;------------------------------------------------------------------------------;
+
+define i1 @t8_shift_of_const0(i32 %x, i32 %y, i32 %z) {
+; CHECK-LABEL: @t8_shift_of_const0(
+; CHECK-NEXT:    [[T0:%.*]] = shl i32 1, [[Y:%.*]]
+; CHECK-NEXT:    [[T1:%.*]] = and i32 [[T0]], [[Z:%.*]]
+; CHECK-NEXT:    [[T2:%.*]] = icmp eq i32 [[T1]], 0
+; CHECK-NEXT:    ret i1 [[T2]]
+;
+  %t0 = shl i32 1, %y
+  %t1 = and i32 %t0, %z
+  %t2 = icmp eq i32 %t1, 0
+  ret i1 %t2
+}
+define i1 @t9_shift_of_const1(i32 %x, i32 %y, i32 %z) {
+; CHECK-LABEL: @t9_shift_of_const1(
+; CHECK-NEXT:    [[T0:%.*]] = lshr i32 1, [[Y:%.*]]
+; CHECK-NEXT:    [[T1:%.*]] = and i32 [[T0]], [[Z:%.*]]
+; CHECK-NEXT:    [[T2:%.*]] = icmp eq i32 [[T1]], 0
+; CHECK-NEXT:    ret i1 [[T2]]
+;
+  %t0 = lshr i32 1, %y
+  %t1 = and i32 %t0, %z
+  %t2 = icmp eq i32 %t1, 0
+  ret i1 %t2
+}
+
+define i1 @t10_and_with_const0(i32 %x, i32 %y, i32 %z) {
+; CHECK-LABEL: @t10_and_with_const0(
+; CHECK-NEXT:    [[TMP1:%.*]] = lshr i32 1, [[Y:%.*]]
+; CHECK-NEXT:    [[TMP2:%.*]] = and i32 [[TMP1]], [[X:%.*]]
+; CHECK-NEXT:    [[T2:%.*]] = icmp eq i32 [[TMP2]], 0
+; CHECK-NEXT:    ret i1 [[T2]]
+;
+  %t0 = shl i32 %x, %y
+  %t1 = and i32 %t0, 1
+  %t2 = icmp eq i32 %t1, 0
+  ret i1 %t2
+}
+define i1 @t11_and_with_const1(i32 %x, i32 %y, i32 %z) {
+; CHECK-LABEL: @t11_and_with_const1(
+; CHECK-NEXT:    [[TMP1:%.*]] = shl i32 1, [[Y:%.*]]
+; CHECK-NEXT:    [[TMP2:%.*]] = and i32 [[TMP1]], [[X:%.*]]
+; CHECK-NEXT:    [[T2:%.*]] = icmp eq i32 [[TMP2]], 0
+; CHECK-NEXT:    ret i1 [[T2]]
+;
+  %t0 = lshr i32 %x, %y
+  %t1 = and i32 %t0, 1
+  %t2 = icmp eq i32 %t1, 0
+  ret i1 %t2
+}
+
+;------------------------------------------------------------------------------;
+; Negative test
+;------------------------------------------------------------------------------;
+
+define i1 @n8(i32 %x, i32 %y, i32 %z) {
+; CHECK-LABEL: @n8(
+; CHECK-NEXT:    [[T0:%.*]] = shl i32 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    [[T1:%.*]] = and i32 [[T0]], [[Z:%.*]]
+; CHECK-NEXT:    [[T2:%.*]] = icmp eq i32 [[T1]], 1
+; CHECK-NEXT:    ret i1 [[T2]]
+;
+  %t0 = shl i32 %x, %y
+  %t1 = and i32 %t0, %z
+  %t2 = icmp eq i32 %t1, 1 ; not with '0'
+  ret i1 %t2
+}