[llvm] 2d712fb - [InstCombine] Add ctpop -> cttz combine tests (PR43513)

[Simon Pilgrim via llvm-commits]

Author: Simon Pilgrim
Date: 2020-03-21T19:30:22Z
New Revision: 2d712fb75584ca8a6427199ca144407155e4b9b5

URL: https://github.com/llvm/llvm-project/commit/2d712fb75584ca8a6427199ca144407155e4b9b5
DIFF: https://github.com/llvm/llvm-project/commit/2d712fb75584ca8a6427199ca144407155e4b9b5.diff

LOG: [InstCombine] Add ctpop -> cttz combine tests (PR43513)

Added: 
    llvm/test/Transforms/InstCombine/ctpop-cttz.ll

Modified: 
    

Removed: 
    


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diff  --git a/llvm/test/Transforms/InstCombine/ctpop-cttz.ll b/llvm/test/Transforms/InstCombine/ctpop-cttz.ll
new file mode 100644
index 000000000000..52e7ef5eb3c1
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/ctpop-cttz.ll
@@ -0,0 +1,69 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -S -instcombine | FileCheck %s
+
+declare i32 @llvm.ctpop.i32(i32)
+declare <2 x i32> @llvm.ctpop.v2i32(<2 x i32>)
+
+; PR43513
+; __builtin_popcount(i | -i) -> 32 - __builtin_cttz(i, false)
+define i32 @ctpop1(i32 %0) {
+; CHECK-LABEL: @ctpop1(
+; CHECK-NEXT:    [[TMP2:%.*]] = sub i32 0, [[TMP0:%.*]]
+; CHECK-NEXT:    [[TMP3:%.*]] = or i32 [[TMP2]], [[TMP0]]
+; CHECK-NEXT:    [[TMP4:%.*]] = tail call i32 @llvm.ctpop.i32(i32 [[TMP3]]), !range !0
+; CHECK-NEXT:    [[TMP5:%.*]] = sub nuw nsw i32 32, [[TMP4]]
+; CHECK-NEXT:    ret i32 [[TMP5]]
+;
+  %2 = sub i32 0, %0
+  %3 = or i32 %2, %0
+  %4 = tail call i32 @llvm.ctpop.i32(i32 %3)
+  %5 = sub i32 32, %4
+  ret i32 %5
+}
+
+define <2 x i32> @ctpop1v(<2 x i32> %0) {
+; CHECK-LABEL: @ctpop1v(
+; CHECK-NEXT:    [[TMP2:%.*]] = sub <2 x i32> zeroinitializer, [[TMP0:%.*]]
+; CHECK-NEXT:    [[TMP3:%.*]] = or <2 x i32> [[TMP2]], [[TMP0]]
+; CHECK-NEXT:    [[TMP4:%.*]] = tail call <2 x i32> @llvm.ctpop.v2i32(<2 x i32> [[TMP3]])
+; CHECK-NEXT:    [[TMP5:%.*]] = sub nsw <2 x i32> <i32 32, i32 32>, [[TMP4]]
+; CHECK-NEXT:    ret <2 x i32> [[TMP5]]
+;
+  %2 = sub <2 x i32> zeroinitializer, %0
+  %3 = or <2 x i32> %2, %0
+  %4 = tail call <2 x i32> @llvm.ctpop.v2i32(<2 x i32> %3)
+  %5 = sub <2 x i32> <i32 32, i32 32>, %4
+  ret <2 x i32> %5
+}
+
+; PR43513
+; __builtin_popcount(~i & (i-1)) -> __builtin_cttz(i, false)
+define i32 @ctpop2(i32 %0) {
+; CHECK-LABEL: @ctpop2(
+; CHECK-NEXT:    [[TMP2:%.*]] = xor i32 [[TMP0:%.*]], -1
+; CHECK-NEXT:    [[TMP3:%.*]] = add i32 [[TMP0]], -1
+; CHECK-NEXT:    [[TMP4:%.*]] = and i32 [[TMP3]], [[TMP2]]
+; CHECK-NEXT:    [[TMP5:%.*]] = tail call i32 @llvm.ctpop.i32(i32 [[TMP4]]), !range !0
+; CHECK-NEXT:    ret i32 [[TMP5]]
+;
+  %2 = xor i32 %0, -1
+  %3 = add i32 %0, -1
+  %4 = and i32 %3, %2
+  %5 = tail call i32 @llvm.ctpop.i32(i32 %4)
+  ret i32 %5
+}
+
+define <2 x i32> @ctpop2v(<2 x i32> %0) {
+; CHECK-LABEL: @ctpop2v(
+; CHECK-NEXT:    [[TMP2:%.*]] = xor <2 x i32> [[TMP0:%.*]], <i32 -1, i32 -1>
+; CHECK-NEXT:    [[TMP3:%.*]] = add <2 x i32> [[TMP0]], <i32 -1, i32 -1>
+; CHECK-NEXT:    [[TMP4:%.*]] = and <2 x i32> [[TMP3]], [[TMP2]]
+; CHECK-NEXT:    [[TMP5:%.*]] = tail call <2 x i32> @llvm.ctpop.v2i32(<2 x i32> [[TMP4]])
+; CHECK-NEXT:    ret <2 x i32> [[TMP5]]
+;
+  %2 = xor <2 x i32> %0, <i32 -1, i32 -1>
+  %3 = add <2 x i32> %0, <i32 -1, i32 -1>
+  %4 = and <2 x i32> %3, %2
+  %5 = tail call <2 x i32> @llvm.ctpop.v2i32(<2 x i32> %4)
+  ret <2 x i32> %5
+}