[llvm] 8633a0d - [NFC][InstCombine] Better tests for x s/EXACT (1 << y) pattern

[Roman Lebedev via llvm-commits]

Author: Roman Lebedev
Date: 2020-08-06T23:37:15+03:00
New Revision: 8633a0d985f1abc8f81dba5f699d5df627e6a9f1

URL: https://github.com/llvm/llvm-project/commit/8633a0d985f1abc8f81dba5f699d5df627e6a9f1
DIFF: https://github.com/llvm/llvm-project/commit/8633a0d985f1abc8f81dba5f699d5df627e6a9f1.diff

LOG: [NFC][InstCombine] Better tests for  x s/EXACT (1 << y)  pattern

Added: 
    llvm/test/Transforms/InstCombine/sdiv-exact-by-power-of-two.ll

Modified: 
    

Removed: 
    


################################################################################
diff  --git a/llvm/test/Transforms/InstCombine/sdiv-exact-by-power-of-two.ll b/llvm/test/Transforms/InstCombine/sdiv-exact-by-power-of-two.ll
new file mode 100644
index 000000000000..f8bcff913902
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/sdiv-exact-by-power-of-two.ll
@@ -0,0 +1,68 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt %s -instcombine -S | FileCheck %s
+
+; Fold
+;   x s/EXACT (1 << y)
+; to
+;   x a>>EXACT y
+; iff 1<<y is non-negative
+
+define i8 @t0(i8 %x) {
+; CHECK-LABEL: @t0(
+; CHECK-NEXT:    [[DIV:%.*]] = ashr exact i8 [[X:%.*]], 5
+; CHECK-NEXT:    ret i8 [[DIV]]
+;
+  %div = sdiv exact i8 %x, 32
+  ret i8 %div
+}
+define i8 @n1(i8 %x) {
+; CHECK-LABEL: @n1(
+; CHECK-NEXT:    [[DIV:%.*]] = sdiv i8 [[X:%.*]], 32
+; CHECK-NEXT:    ret i8 [[DIV]]
+;
+  %div = sdiv i8 %x, 32 ; not exact
+  ret i8 %div
+}
+define i8 @n2(i8 %x) {
+; CHECK-LABEL: @n2(
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp eq i8 [[X:%.*]], -128
+; CHECK-NEXT:    [[DIV:%.*]] = zext i1 [[TMP1]] to i8
+; CHECK-NEXT:    ret i8 [[DIV]]
+;
+  %div = sdiv i8 %x, 128 ; negative divisor
+  ret i8 %div
+}
+
+define <2 x i8> @t3_vec_splat(<2 x i8> %x) {
+; CHECK-LABEL: @t3_vec_splat(
+; CHECK-NEXT:    [[DIV:%.*]] = ashr exact <2 x i8> [[X:%.*]], <i8 5, i8 5>
+; CHECK-NEXT:    ret <2 x i8> [[DIV]]
+;
+  %div = sdiv exact <2 x i8> %x, <i8 32, i8 32>
+  ret <2 x i8> %div
+}
+
+define <2 x i8> @t4_vec(<2 x i8> %x) {
+; CHECK-LABEL: @t4_vec(
+; CHECK-NEXT:    [[DIV:%.*]] = sdiv exact <2 x i8> [[X:%.*]], <i8 32, i8 16>
+; CHECK-NEXT:    ret <2 x i8> [[DIV]]
+;
+  %div = sdiv exact <2 x i8> %x, <i8 32, i8 16>
+  ret <2 x i8> %div
+}
+
+define <2 x i8> @n5_vec_undef(<2 x i8> %x) {
+; CHECK-LABEL: @n5_vec_undef(
+; CHECK-NEXT:    ret <2 x i8> undef
+;
+  %div = sdiv exact <2 x i8> %x, <i8 32, i8 undef>
+  ret <2 x i8> %div
+}
+define <2 x i8> @n6_vec_negative(<2 x i8> %x) {
+; CHECK-LABEL: @n6_vec_negative(
+; CHECK-NEXT:    [[DIV:%.*]] = sdiv exact <2 x i8> [[X:%.*]], <i8 32, i8 -128>
+; CHECK-NEXT:    ret <2 x i8> [[DIV]]
+;
+  %div = sdiv exact <2 x i8> %x, <i8 32, i8 128> ; non-non-negative divisor
+  ret <2 x i8> %div
+}