[llvm] [InstCombine] Fold Minimum over Trailing/Leading Bits Counts (PR #90402)

via llvm-commits llvm-commits at lists.llvm.org
Tue Jul 2 10:02:19 PDT 2024


https://github.com/mskamp updated https://github.com/llvm/llvm-project/pull/90402

>From dabdbda8d5903a3ef15cb16206b1fe1c71503183 Mon Sep 17 00:00:00 2001
From: Marius Kamp <msk at posteo.org>
Date: Sat, 27 Apr 2024 17:51:44 +0200
Subject: [PATCH 1/2] [InstCombine][NFC] Add Tests for Minimum over
 Trailing/Leading Bits Counts

---
 .../Transforms/InstCombine/umin_cttz_ctlz.ll  | 382 ++++++++++++++++++
 1 file changed, 382 insertions(+)
 create mode 100644 llvm/test/Transforms/InstCombine/umin_cttz_ctlz.ll

diff --git a/llvm/test/Transforms/InstCombine/umin_cttz_ctlz.ll b/llvm/test/Transforms/InstCombine/umin_cttz_ctlz.ll
new file mode 100644
index 0000000000000..e6e0215e920c5
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/umin_cttz_ctlz.ll
@@ -0,0 +1,382 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 4
+; RUN: opt < %s -passes=instcombine -S | FileCheck %s
+
+define i8 @umin_cttz_i8_zero_undefined(i8 %X) {
+; CHECK-LABEL: define i8 @umin_cttz_i8_zero_undefined(
+; CHECK-SAME: i8 [[X:%.*]]) {
+; CHECK-NEXT:    [[CTTZ:%.*]] = call range(i8 0, 9) i8 @llvm.cttz.i8(i8 [[X]], i1 true)
+; CHECK-NEXT:    [[RET:%.*]] = call i8 @llvm.umin.i8(i8 [[CTTZ]], i8 6)
+; CHECK-NEXT:    ret i8 [[RET]]
+;
+  %cttz = call i8 @llvm.cttz.i8(i8 %X, i1 true)
+  %ret = call i8 @llvm.umin.i8(i8 %cttz, i8 6)
+  ret i8 %ret
+}
+
+define i8 @umin_cttz_i8_zero_defined(i8 %X) {
+; CHECK-LABEL: define i8 @umin_cttz_i8_zero_defined(
+; CHECK-SAME: i8 [[X:%.*]]) {
+; CHECK-NEXT:    [[CTTZ:%.*]] = call range(i8 0, 9) i8 @llvm.cttz.i8(i8 [[X]], i1 false)
+; CHECK-NEXT:    [[RET:%.*]] = call i8 @llvm.umin.i8(i8 [[CTTZ]], i8 6)
+; CHECK-NEXT:    ret i8 [[RET]]
+;
+  %cttz = call i8 @llvm.cttz.i8(i8 %X, i1 false)
+  %ret = call i8 @llvm.umin.i8(i8 %cttz, i8 6)
+  ret i8 %ret
+}
+
+define i8 @umin_cttz_i8_commuted_zero_undefined(i8 %X) {
+; CHECK-LABEL: define i8 @umin_cttz_i8_commuted_zero_undefined(
+; CHECK-SAME: i8 [[X:%.*]]) {
+; CHECK-NEXT:    [[CTTZ:%.*]] = call range(i8 0, 9) i8 @llvm.cttz.i8(i8 [[X]], i1 true)
+; CHECK-NEXT:    [[RET:%.*]] = call i8 @llvm.umin.i8(i8 [[CTTZ]], i8 6)
+; CHECK-NEXT:    ret i8 [[RET]]
+;
+  %cttz = call i8 @llvm.cttz.i8(i8 %X, i1 true)
+  %ret = call i8 @llvm.umin.i8(i8 6, i8 %cttz)
+  ret i8 %ret
+}
+
+define i8 @umin_cttz_i8_negative_ge_bitwidth_zero_undefined(i8 %X) {
+; CHECK-LABEL: define i8 @umin_cttz_i8_negative_ge_bitwidth_zero_undefined(
+; CHECK-SAME: i8 [[X:%.*]]) {
+; CHECK-NEXT:    [[CTTZ:%.*]] = call range(i8 0, 9) i8 @llvm.cttz.i8(i8 [[X]], i1 true)
+; CHECK-NEXT:    ret i8 [[CTTZ]]
+;
+  %cttz = call i8 @llvm.cttz.i8(i8 %X, i1 true)
+  %ret = call i8 @llvm.umin.i8(i8 %cttz, i8 10)
+  ret i8 %ret
+}
+
+define i16 @umin_cttz_i16_zero_undefined(i16 %X) {
+; CHECK-LABEL: define i16 @umin_cttz_i16_zero_undefined(
+; CHECK-SAME: i16 [[X:%.*]]) {
+; CHECK-NEXT:    [[CTTZ:%.*]] = call range(i16 0, 17) i16 @llvm.cttz.i16(i16 [[X]], i1 true)
+; CHECK-NEXT:    [[RET:%.*]] = call i16 @llvm.umin.i16(i16 [[CTTZ]], i16 6)
+; CHECK-NEXT:    ret i16 [[RET]]
+;
+  %cttz = call i16 @llvm.cttz.i16(i16 %X, i1 true)
+  %ret = call i16 @llvm.umin.i16(i16 %cttz, i16 6)
+  ret i16 %ret
+}
+
+define i32 @umin_cttz_i32_zero_undefined(i32 %X) {
+; CHECK-LABEL: define i32 @umin_cttz_i32_zero_undefined(
+; CHECK-SAME: i32 [[X:%.*]]) {
+; CHECK-NEXT:    [[CTTZ:%.*]] = call range(i32 0, 33) i32 @llvm.cttz.i32(i32 [[X]], i1 true)
+; CHECK-NEXT:    [[RET:%.*]] = call i32 @llvm.umin.i32(i32 [[CTTZ]], i32 6)
+; CHECK-NEXT:    ret i32 [[RET]]
+;
+  %cttz = call i32 @llvm.cttz.i32(i32 %X, i1 true)
+  %ret = call i32 @llvm.umin.i32(i32 %cttz, i32 6)
+  ret i32 %ret
+}
+
+define i64 @umin_cttz_i64_zero_undefined(i64 %X) {
+; CHECK-LABEL: define i64 @umin_cttz_i64_zero_undefined(
+; CHECK-SAME: i64 [[X:%.*]]) {
+; CHECK-NEXT:    [[CTTZ:%.*]] = call range(i64 0, 65) i64 @llvm.cttz.i64(i64 [[X]], i1 true)
+; CHECK-NEXT:    [[RET:%.*]] = call i64 @llvm.umin.i64(i64 [[CTTZ]], i64 6)
+; CHECK-NEXT:    ret i64 [[RET]]
+;
+  %cttz = call i64 @llvm.cttz.i64(i64 %X, i1 true)
+  %ret = call i64 @llvm.umin.i64(i64 %cttz, i64 6)
+  ret i64 %ret
+}
+
+define i1 @umin_cttz_i1_zero_undefined(i1 %X) {
+; CHECK-LABEL: define i1 @umin_cttz_i1_zero_undefined(
+; CHECK-SAME: i1 [[X:%.*]]) {
+; CHECK-NEXT:    ret i1 false
+;
+  %cttz = call i1 @llvm.cttz.i1(i1 %X, i1 true)
+  %ret = call i1 @llvm.umin.i1(i1 %cttz, i1 1)
+  ret i1 %ret
+}
+
+define i1 @umin_cttz_i1_zero_defined(i1 %X) {
+; CHECK-LABEL: define i1 @umin_cttz_i1_zero_defined(
+; CHECK-SAME: i1 [[X:%.*]]) {
+; CHECK-NEXT:    [[CTTZ:%.*]] = xor i1 [[X]], true
+; CHECK-NEXT:    ret i1 [[CTTZ]]
+;
+  %cttz = call i1 @llvm.cttz.i1(i1 %X, i1 false)
+  %ret = call i1 @llvm.umin.i1(i1 %cttz, i1 1)
+  ret i1 %ret
+}
+
+define <2 x i32> @umin_cttz_2xi32_splat_zero_undefined(<2 x i32> %X) {
+; CHECK-LABEL: define <2 x i32> @umin_cttz_2xi32_splat_zero_undefined(
+; CHECK-SAME: <2 x i32> [[X:%.*]]) {
+; CHECK-NEXT:    [[CTTZ:%.*]] = call range(i32 0, 33) <2 x i32> @llvm.cttz.v2i32(<2 x i32> [[X]], i1 true)
+; CHECK-NEXT:    [[RET:%.*]] = call <2 x i32> @llvm.umin.v2i32(<2 x i32> [[CTTZ]], <2 x i32> <i32 6, i32 6>)
+; CHECK-NEXT:    ret <2 x i32> [[RET]]
+;
+  %cttz = call <2 x i32> @llvm.cttz.v2i32(<2 x i32> %X, i1 true)
+  %ret = call <2 x i32> @llvm.umin.v2i32(<2 x i32> %cttz, <2 x i32> <i32 6, i32 6>)
+  ret <2 x i32> %ret
+}
+
+define <2 x i32> @umin_cttz_2xi32_splat_poison_zero_undefined(<2 x i32> %X) {
+; CHECK-LABEL: define <2 x i32> @umin_cttz_2xi32_splat_poison_zero_undefined(
+; CHECK-SAME: <2 x i32> [[X:%.*]]) {
+; CHECK-NEXT:    [[CTTZ:%.*]] = call range(i32 0, 33) <2 x i32> @llvm.cttz.v2i32(<2 x i32> [[X]], i1 true)
+; CHECK-NEXT:    [[RET:%.*]] = call <2 x i32> @llvm.umin.v2i32(<2 x i32> [[CTTZ]], <2 x i32> <i32 6, i32 poison>)
+; CHECK-NEXT:    ret <2 x i32> [[RET]]
+;
+  %cttz = call <2 x i32> @llvm.cttz.v2i32(<2 x i32> %X, i1 true)
+  %ret = call <2 x i32> @llvm.umin.v2i32(<2 x i32> %cttz, <2 x i32> <i32 6, i32 poison>)
+  ret <2 x i32> %ret
+}
+
+define <2 x i32> @umin_cttz_2xi32_no_splat_all_lt_bitwidth_zero_undefined(<2 x i32> %X) {
+; CHECK-LABEL: define <2 x i32> @umin_cttz_2xi32_no_splat_all_lt_bitwidth_zero_undefined(
+; CHECK-SAME: <2 x i32> [[X:%.*]]) {
+; CHECK-NEXT:    [[CTTZ:%.*]] = call range(i32 0, 33) <2 x i32> @llvm.cttz.v2i32(<2 x i32> [[X]], i1 true)
+; CHECK-NEXT:    [[RET:%.*]] = call <2 x i32> @llvm.umin.v2i32(<2 x i32> [[CTTZ]], <2 x i32> <i32 6, i32 0>)
+; CHECK-NEXT:    ret <2 x i32> [[RET]]
+;
+  %cttz = call <2 x i32> @llvm.cttz.v2i32(<2 x i32> %X, i1 true)
+  %ret = call <2 x i32> @llvm.umin.v2i32(<2 x i32> %cttz, <2 x i32> <i32 6, i32 0>)
+  ret <2 x i32> %ret
+}
+
+define <2 x i32> @umin_cttz_2xi32_negative_no_splat_some_lt_bitwidth_zero_undefined(<2 x i32> %X) {
+; CHECK-LABEL: define <2 x i32> @umin_cttz_2xi32_negative_no_splat_some_lt_bitwidth_zero_undefined(
+; CHECK-SAME: <2 x i32> [[X:%.*]]) {
+; CHECK-NEXT:    [[CTTZ:%.*]] = call range(i32 0, 33) <2 x i32> @llvm.cttz.v2i32(<2 x i32> [[X]], i1 true)
+; CHECK-NEXT:    [[RET:%.*]] = call <2 x i32> @llvm.umin.v2i32(<2 x i32> [[CTTZ]], <2 x i32> <i32 6, i32 64>)
+; CHECK-NEXT:    ret <2 x i32> [[RET]]
+;
+  %cttz = call <2 x i32> @llvm.cttz.v2i32(<2 x i32> %X, i1 true)
+  %ret = call <2 x i32> @llvm.umin.v2i32(<2 x i32> %cttz, <2 x i32> <i32 6, i32 64>)
+  ret <2 x i32> %ret
+}
+
+define <2 x i32> @umin_cttz_2xi32_negative_no_splat_none_lt_bitwidth_zero_undefined(<2 x i32> %X) {
+; CHECK-LABEL: define <2 x i32> @umin_cttz_2xi32_negative_no_splat_none_lt_bitwidth_zero_undefined(
+; CHECK-SAME: <2 x i32> [[X:%.*]]) {
+; CHECK-NEXT:    [[CTTZ:%.*]] = call range(i32 0, 33) <2 x i32> @llvm.cttz.v2i32(<2 x i32> [[X]], i1 true)
+; CHECK-NEXT:    [[RET:%.*]] = call <2 x i32> @llvm.umin.v2i32(<2 x i32> [[CTTZ]], <2 x i32> <i32 32, i32 64>)
+; CHECK-NEXT:    ret <2 x i32> [[RET]]
+;
+  %cttz = call <2 x i32> @llvm.cttz.v2i32(<2 x i32> %X, i1 true)
+  %ret = call <2 x i32> @llvm.umin.v2i32(<2 x i32> %cttz, <2 x i32> <i32 32, i32 64>)
+  ret <2 x i32> %ret
+}
+
+define i16 @umin_cttz_i16_negative_non_constant(i16 %X, i16 %Y) {
+; CHECK-LABEL: define i16 @umin_cttz_i16_negative_non_constant(
+; CHECK-SAME: i16 [[X:%.*]], i16 [[Y:%.*]]) {
+; CHECK-NEXT:    [[CTTZ:%.*]] = call range(i16 0, 17) i16 @llvm.cttz.i16(i16 [[X]], i1 true)
+; CHECK-NEXT:    [[RET:%.*]] = call i16 @llvm.umin.i16(i16 [[CTTZ]], i16 [[Y]])
+; CHECK-NEXT:    ret i16 [[RET]]
+;
+  %cttz = call i16 @llvm.cttz.i16(i16 %X, i1 true)
+  %ret = call i16 @llvm.umin.i16(i16 %cttz, i16 %Y)
+  ret i16 %ret
+}
+
+define i16 @umin_cttz_i16_negative_two_uses(i16 %X) {
+; CHECK-LABEL: define i16 @umin_cttz_i16_negative_two_uses(
+; CHECK-SAME: i16 [[X:%.*]]) {
+; CHECK-NEXT:    [[CTTZ:%.*]] = call range(i16 0, 17) i16 @llvm.cttz.i16(i16 [[X]], i1 true)
+; CHECK-NEXT:    [[OP0:%.*]] = call i16 @llvm.umin.i16(i16 [[CTTZ]], i16 6)
+; CHECK-NEXT:    [[RET:%.*]] = add nuw nsw i16 [[CTTZ]], [[OP0]]
+; CHECK-NEXT:    ret i16 [[RET]]
+;
+  %cttz = call i16 @llvm.cttz.i16(i16 %X, i1 true)
+  %op0 = call i16 @llvm.umin.i16(i16 %cttz, i16 6)
+  %ret = add i16 %cttz, %op0
+  ret i16 %ret
+}
+
+define i8 @umin_ctlz_i8_zero_undefined(i8 %X) {
+; CHECK-LABEL: define i8 @umin_ctlz_i8_zero_undefined(
+; CHECK-SAME: i8 [[X:%.*]]) {
+; CHECK-NEXT:    [[CTLZ:%.*]] = call range(i8 0, 9) i8 @llvm.ctlz.i8(i8 [[X]], i1 true)
+; CHECK-NEXT:    [[RET:%.*]] = call i8 @llvm.umin.i8(i8 [[CTLZ]], i8 6)
+; CHECK-NEXT:    ret i8 [[RET]]
+;
+  %ctlz = call i8 @llvm.ctlz.i8(i8 %X, i1 true)
+  %ret = call i8 @llvm.umin.i8(i8 %ctlz, i8 6)
+  ret i8 %ret
+}
+
+define i8 @umin_ctlz_i8_zero_defined(i8 %X) {
+; CHECK-LABEL: define i8 @umin_ctlz_i8_zero_defined(
+; CHECK-SAME: i8 [[X:%.*]]) {
+; CHECK-NEXT:    [[CTLZ:%.*]] = call range(i8 0, 9) i8 @llvm.ctlz.i8(i8 [[X]], i1 false)
+; CHECK-NEXT:    [[RET:%.*]] = call i8 @llvm.umin.i8(i8 [[CTLZ]], i8 6)
+; CHECK-NEXT:    ret i8 [[RET]]
+;
+  %ctlz = call i8 @llvm.ctlz.i8(i8 %X, i1 false)
+  %ret = call i8 @llvm.umin.i8(i8 %ctlz, i8 6)
+  ret i8 %ret
+}
+
+define i8 @umin_ctlz_i8_commuted_zero_undefined(i8 %X) {
+; CHECK-LABEL: define i8 @umin_ctlz_i8_commuted_zero_undefined(
+; CHECK-SAME: i8 [[X:%.*]]) {
+; CHECK-NEXT:    [[CTLZ:%.*]] = call range(i8 0, 9) i8 @llvm.ctlz.i8(i8 [[X]], i1 true)
+; CHECK-NEXT:    [[RET:%.*]] = call i8 @llvm.umin.i8(i8 [[CTLZ]], i8 6)
+; CHECK-NEXT:    ret i8 [[RET]]
+;
+  %ctlz = call i8 @llvm.ctlz.i8(i8 %X, i1 true)
+  %ret = call i8 @llvm.umin.i8(i8 6, i8 %ctlz)
+  ret i8 %ret
+}
+
+define i8 @umin_ctlz_i8_negative_ge_bitwidth_zero_undefined(i8 %X) {
+; CHECK-LABEL: define i8 @umin_ctlz_i8_negative_ge_bitwidth_zero_undefined(
+; CHECK-SAME: i8 [[X:%.*]]) {
+; CHECK-NEXT:    [[CTLZ:%.*]] = call range(i8 0, 9) i8 @llvm.ctlz.i8(i8 [[X]], i1 true)
+; CHECK-NEXT:    ret i8 [[CTLZ]]
+;
+  %ctlz = call i8 @llvm.ctlz.i8(i8 %X, i1 true)
+  %ret = call i8 @llvm.umin.i8(i8 %ctlz, i8 10)
+  ret i8 %ret
+}
+
+define i16 @umin_ctlz_i16_zero_undefined(i16 %X) {
+; CHECK-LABEL: define i16 @umin_ctlz_i16_zero_undefined(
+; CHECK-SAME: i16 [[X:%.*]]) {
+; CHECK-NEXT:    [[CTLZ:%.*]] = call range(i16 0, 17) i16 @llvm.ctlz.i16(i16 [[X]], i1 true)
+; CHECK-NEXT:    [[RET:%.*]] = call i16 @llvm.umin.i16(i16 [[CTLZ]], i16 6)
+; CHECK-NEXT:    ret i16 [[RET]]
+;
+  %ctlz = call i16 @llvm.ctlz.i16(i16 %X, i1 true)
+  %ret = call i16 @llvm.umin.i16(i16 %ctlz, i16 6)
+  ret i16 %ret
+}
+
+define i32 @umin_ctlz_i32_zero_undefined(i32 %X) {
+; CHECK-LABEL: define i32 @umin_ctlz_i32_zero_undefined(
+; CHECK-SAME: i32 [[X:%.*]]) {
+; CHECK-NEXT:    [[CTLZ:%.*]] = call range(i32 0, 33) i32 @llvm.ctlz.i32(i32 [[X]], i1 true)
+; CHECK-NEXT:    [[RET:%.*]] = call i32 @llvm.umin.i32(i32 [[CTLZ]], i32 6)
+; CHECK-NEXT:    ret i32 [[RET]]
+;
+  %ctlz = call i32 @llvm.ctlz.i32(i32 %X, i1 true)
+  %ret = call i32 @llvm.umin.i32(i32 %ctlz, i32 6)
+  ret i32 %ret
+}
+
+define i64 @umin_ctlz_i64_zero_undefined(i64 %X) {
+; CHECK-LABEL: define i64 @umin_ctlz_i64_zero_undefined(
+; CHECK-SAME: i64 [[X:%.*]]) {
+; CHECK-NEXT:    [[CTLZ:%.*]] = call range(i64 0, 65) i64 @llvm.ctlz.i64(i64 [[X]], i1 true)
+; CHECK-NEXT:    [[RET:%.*]] = call i64 @llvm.umin.i64(i64 [[CTLZ]], i64 6)
+; CHECK-NEXT:    ret i64 [[RET]]
+;
+  %ctlz = call i64 @llvm.ctlz.i64(i64 %X, i1 true)
+  %ret = call i64 @llvm.umin.i64(i64 %ctlz, i64 6)
+  ret i64 %ret
+}
+
+define i1 @umin_ctlz_i1_zero_undefined(i1 %X) {
+; CHECK-LABEL: define i1 @umin_ctlz_i1_zero_undefined(
+; CHECK-SAME: i1 [[X:%.*]]) {
+; CHECK-NEXT:    ret i1 false
+;
+  %ctlz = call i1 @llvm.ctlz.i1(i1 %X, i1 true)
+  %ret = call i1 @llvm.umin.i1(i1 %ctlz, i1 1)
+  ret i1 %ret
+}
+
+define i1 @umin_ctlz_i1_zero_defined(i1 %X) {
+; CHECK-LABEL: define i1 @umin_ctlz_i1_zero_defined(
+; CHECK-SAME: i1 [[X:%.*]]) {
+; CHECK-NEXT:    [[CTLZ:%.*]] = xor i1 [[X]], true
+; CHECK-NEXT:    ret i1 [[CTLZ]]
+;
+  %ctlz = call i1 @llvm.ctlz.i1(i1 %X, i1 false)
+  %ret = call i1 @llvm.umin.i1(i1 %ctlz, i1 1)
+  ret i1 %ret
+}
+
+define <2 x i32> @umin_ctlz_2xi32_splat_zero_undefined(<2 x i32> %X) {
+; CHECK-LABEL: define <2 x i32> @umin_ctlz_2xi32_splat_zero_undefined(
+; CHECK-SAME: <2 x i32> [[X:%.*]]) {
+; CHECK-NEXT:    [[CTLZ:%.*]] = call range(i32 0, 33) <2 x i32> @llvm.ctlz.v2i32(<2 x i32> [[X]], i1 true)
+; CHECK-NEXT:    [[RET:%.*]] = call <2 x i32> @llvm.umin.v2i32(<2 x i32> [[CTLZ]], <2 x i32> <i32 6, i32 6>)
+; CHECK-NEXT:    ret <2 x i32> [[RET]]
+;
+  %ctlz = call <2 x i32> @llvm.ctlz.v2i32(<2 x i32> %X, i1 true)
+  %ret = call <2 x i32> @llvm.umin.v2i32(<2 x i32> %ctlz, <2 x i32> <i32 6, i32 6>)
+  ret <2 x i32> %ret
+}
+
+define <2 x i32> @umin_ctlz_2xi32_splat_poison_zero_undefined(<2 x i32> %X) {
+; CHECK-LABEL: define <2 x i32> @umin_ctlz_2xi32_splat_poison_zero_undefined(
+; CHECK-SAME: <2 x i32> [[X:%.*]]) {
+; CHECK-NEXT:    [[CTLZ:%.*]] = call range(i32 0, 33) <2 x i32> @llvm.ctlz.v2i32(<2 x i32> [[X]], i1 true)
+; CHECK-NEXT:    [[RET:%.*]] = call <2 x i32> @llvm.umin.v2i32(<2 x i32> [[CTLZ]], <2 x i32> <i32 6, i32 poison>)
+; CHECK-NEXT:    ret <2 x i32> [[RET]]
+;
+  %ctlz = call <2 x i32> @llvm.ctlz.v2i32(<2 x i32> %X, i1 true)
+  %ret = call <2 x i32> @llvm.umin.v2i32(<2 x i32> %ctlz, <2 x i32> <i32 6, i32 poison>)
+  ret <2 x i32> %ret
+}
+
+define <2 x i32> @umin_ctlz_2xi32_no_splat_all_lt_bitwidth_zero_undefined(<2 x i32> %X) {
+; CHECK-LABEL: define <2 x i32> @umin_ctlz_2xi32_no_splat_all_lt_bitwidth_zero_undefined(
+; CHECK-SAME: <2 x i32> [[X:%.*]]) {
+; CHECK-NEXT:    [[CTLZ:%.*]] = call range(i32 0, 33) <2 x i32> @llvm.ctlz.v2i32(<2 x i32> [[X]], i1 true)
+; CHECK-NEXT:    [[RET:%.*]] = call <2 x i32> @llvm.umin.v2i32(<2 x i32> [[CTLZ]], <2 x i32> <i32 6, i32 0>)
+; CHECK-NEXT:    ret <2 x i32> [[RET]]
+;
+  %ctlz = call <2 x i32> @llvm.ctlz.v2i32(<2 x i32> %X, i1 true)
+  %ret = call <2 x i32> @llvm.umin.v2i32(<2 x i32> %ctlz, <2 x i32> <i32 6, i32 0>)
+  ret <2 x i32> %ret
+}
+
+define <2 x i32> @umin_ctlz_2xi32_negative_no_splat_some_lt_bitwidth_zero_undefined(<2 x i32> %X) {
+; CHECK-LABEL: define <2 x i32> @umin_ctlz_2xi32_negative_no_splat_some_lt_bitwidth_zero_undefined(
+; CHECK-SAME: <2 x i32> [[X:%.*]]) {
+; CHECK-NEXT:    [[CTLZ:%.*]] = call range(i32 0, 33) <2 x i32> @llvm.ctlz.v2i32(<2 x i32> [[X]], i1 true)
+; CHECK-NEXT:    [[RET:%.*]] = call <2 x i32> @llvm.umin.v2i32(<2 x i32> [[CTLZ]], <2 x i32> <i32 6, i32 64>)
+; CHECK-NEXT:    ret <2 x i32> [[RET]]
+;
+  %ctlz = call <2 x i32> @llvm.ctlz.v2i32(<2 x i32> %X, i1 true)
+  %ret = call <2 x i32> @llvm.umin.v2i32(<2 x i32> %ctlz, <2 x i32> <i32 6, i32 64>)
+  ret <2 x i32> %ret
+}
+
+define <2 x i32> @umin_ctlz_2xi32_negative_no_splat_none_lt_bitwidth_zero_undefined(<2 x i32> %X) {
+; CHECK-LABEL: define <2 x i32> @umin_ctlz_2xi32_negative_no_splat_none_lt_bitwidth_zero_undefined(
+; CHECK-SAME: <2 x i32> [[X:%.*]]) {
+; CHECK-NEXT:    [[CTLZ:%.*]] = call range(i32 0, 33) <2 x i32> @llvm.ctlz.v2i32(<2 x i32> [[X]], i1 true)
+; CHECK-NEXT:    [[RET:%.*]] = call <2 x i32> @llvm.umin.v2i32(<2 x i32> [[CTLZ]], <2 x i32> <i32 32, i32 64>)
+; CHECK-NEXT:    ret <2 x i32> [[RET]]
+;
+  %ctlz = call <2 x i32> @llvm.ctlz.v2i32(<2 x i32> %X, i1 true)
+  %ret = call <2 x i32> @llvm.umin.v2i32(<2 x i32> %ctlz, <2 x i32> <i32 32, i32 64>)
+  ret <2 x i32> %ret
+}
+
+define i16 @umin_ctlz_i16_negative_non_constant(i16 %X, i16 %Y) {
+; CHECK-LABEL: define i16 @umin_ctlz_i16_negative_non_constant(
+; CHECK-SAME: i16 [[X:%.*]], i16 [[Y:%.*]]) {
+; CHECK-NEXT:    [[CTLZ:%.*]] = call range(i16 0, 17) i16 @llvm.ctlz.i16(i16 [[X]], i1 true)
+; CHECK-NEXT:    [[RET:%.*]] = call i16 @llvm.umin.i16(i16 [[CTLZ]], i16 [[Y]])
+; CHECK-NEXT:    ret i16 [[RET]]
+;
+  %ctlz = call i16 @llvm.ctlz.i16(i16 %X, i1 true)
+  %ret = call i16 @llvm.umin.i16(i16 %ctlz, i16 %Y)
+  ret i16 %ret
+}
+
+define i16 @umin_ctlz_i16_negative_two_uses(i16 %X) {
+; CHECK-LABEL: define i16 @umin_ctlz_i16_negative_two_uses(
+; CHECK-SAME: i16 [[X:%.*]]) {
+; CHECK-NEXT:    [[CTTZ:%.*]] = call range(i16 0, 17) i16 @llvm.ctlz.i16(i16 [[X]], i1 true)
+; CHECK-NEXT:    [[OP0:%.*]] = call i16 @llvm.umin.i16(i16 [[CTTZ]], i16 6)
+; CHECK-NEXT:    [[RET:%.*]] = add nuw nsw i16 [[CTTZ]], [[OP0]]
+; CHECK-NEXT:    ret i16 [[RET]]
+;
+  %ctlz = call i16 @llvm.ctlz.i16(i16 %X, i1 true)
+  %op0 = call i16 @llvm.umin.i16(i16 %ctlz, i16 6)
+  %ret = add i16 %ctlz, %op0
+  ret i16 %ret
+}

>From ff7c786a45bcad3f0d2773dafc6f2ae3abe01fd5 Mon Sep 17 00:00:00 2001
From: Marius Kamp <msk at posteo.org>
Date: Sat, 27 Apr 2024 19:46:42 +0200
Subject: [PATCH 2/2] [InstCombine] Fold Minimum over Trailing/Leading Bits
 Counts (#90000)

The new transformation folds `umin(cttz(x), c)` to `cttz(x | (1 << c))`
and `umin(ctlz(x), c)` to `ctlz(x | ((1 << (bitwidth - 1)) >> c))`. The
transformation is only implemented for constant `c` to not increase the
number of instructions.

The idea of the transformation is to set the c-th lowest (for `cttz`) or
highest (for `ctlz`) bit in the operand. In this way, the `cttz` or
`ctlz` instruction always returns at most `c`.

Alive2 proofs: https://alive2.llvm.org/ce/z/y8Hdb8
---
 .../InstCombine/InstCombineCalls.cpp          | 50 ++++++++++
 .../Transforms/InstCombine/umin_cttz_ctlz.ll  | 96 +++++++++----------
 2 files changed, 98 insertions(+), 48 deletions(-)

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
index 1913ef92c16c0..83e8d7dfe9abe 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -1428,6 +1428,44 @@ static Instruction *foldBitOrderCrossLogicOp(Value *V,
   return nullptr;
 }
 
+/// Fold an unsigned minimum of trailing or leading zero bits counts:
+///   umin(cttz(CtOp, ZeroUndef), ConstOp) --> cttz(CtOp | (1 << ConstOp))
+///   umin(ctlz(CtOp, ZeroUndef), ConstOp) --> ctlz(CtOp | ((1 << (bitwidth-1))
+///                                              >> ConstOp))
+template <Intrinsic::ID IntrID>
+static Value *
+foldMinimumOverTrailingOrLeadingZeroCount(Value *I0, Value *I1,
+                                          const DataLayout &DL,
+                                          InstCombiner::BuilderTy &Builder) {
+  static_assert(IntrID == Intrinsic::cttz || IntrID == Intrinsic::ctlz,
+                "This helper only supports cttz and ctlz intrinsics");
+
+  Value *CtOp;
+  Value *ZeroUndef;
+  if (!match(I0, m_OneUse(
+                     m_Intrinsic<IntrID>(m_Value(CtOp), m_Value(ZeroUndef))))) {
+    return nullptr;
+  }
+
+  auto BitWidth = I1->getType()->getScalarSizeInBits();
+  auto LessBitWidth = [BitWidth](auto &C) { return C.ult(BitWidth); };
+  if (!match(I1, m_CheckedInt(LessBitWidth))) {
+    // We have a constant >= BitWidth (which can be handled by CVP)
+    // or a non-splat vector with elements < and >= BitWidth
+    return nullptr;
+  }
+
+  auto *Ty = I1->getType();
+  Constant *NewConst = ConstantFoldBinaryOpOperands(
+      IntrID == Intrinsic::cttz ? Instruction::Shl : Instruction::LShr,
+      IntrID == Intrinsic::cttz
+          ? ConstantInt::get(Ty, 1)
+          : ConstantInt::get(Ty, APInt::getSignedMinValue(BitWidth)),
+      cast<Constant>(I1), DL);
+  return Builder.CreateBinaryIntrinsic(IntrID, Builder.CreateOr(CtOp, NewConst),
+                                       ZeroUndef);
+}
+
 /// CallInst simplification. This mostly only handles folding of intrinsic
 /// instructions. For normal calls, it allows visitCallBase to do the heavy
 /// lifting.
@@ -1633,6 +1671,18 @@ Instruction *InstCombinerImpl::visitCallInst(CallInst &CI) {
       Value *Cmp = Builder.CreateICmpNE(I0, Zero);
       return CastInst::Create(Instruction::ZExt, Cmp, II->getType());
     }
+    // umin(cttz(x), const) --> cttz(x | (1 << const))
+    if (Value *FoldedCttz =
+            foldMinimumOverTrailingOrLeadingZeroCount<Intrinsic::cttz>(
+                I0, I1, DL, Builder)) {
+      return replaceInstUsesWith(*II, FoldedCttz);
+    }
+    // umin(ctlz(x), const) --> ctlz(x | ((1 << (bitwidth - 1) >> const)))
+    if (Value *FoldedCtlz =
+            foldMinimumOverTrailingOrLeadingZeroCount<Intrinsic::ctlz>(
+                I0, I1, DL, Builder)) {
+      return replaceInstUsesWith(*II, FoldedCtlz);
+    }
     [[fallthrough]];
   }
   case Intrinsic::umax: {
diff --git a/llvm/test/Transforms/InstCombine/umin_cttz_ctlz.ll b/llvm/test/Transforms/InstCombine/umin_cttz_ctlz.ll
index e6e0215e920c5..0d87122660cfa 100644
--- a/llvm/test/Transforms/InstCombine/umin_cttz_ctlz.ll
+++ b/llvm/test/Transforms/InstCombine/umin_cttz_ctlz.ll
@@ -4,8 +4,8 @@
 define i8 @umin_cttz_i8_zero_undefined(i8 %X) {
 ; CHECK-LABEL: define i8 @umin_cttz_i8_zero_undefined(
 ; CHECK-SAME: i8 [[X:%.*]]) {
-; CHECK-NEXT:    [[CTTZ:%.*]] = call range(i8 0, 9) i8 @llvm.cttz.i8(i8 [[X]], i1 true)
-; CHECK-NEXT:    [[RET:%.*]] = call i8 @llvm.umin.i8(i8 [[CTTZ]], i8 6)
+; CHECK-NEXT:    [[TMP1:%.*]] = or i8 [[X]], 64
+; CHECK-NEXT:    [[RET:%.*]] = call range(i8 0, 7) i8 @llvm.cttz.i8(i8 [[TMP1]], i1 true)
 ; CHECK-NEXT:    ret i8 [[RET]]
 ;
   %cttz = call i8 @llvm.cttz.i8(i8 %X, i1 true)
@@ -16,8 +16,8 @@ define i8 @umin_cttz_i8_zero_undefined(i8 %X) {
 define i8 @umin_cttz_i8_zero_defined(i8 %X) {
 ; CHECK-LABEL: define i8 @umin_cttz_i8_zero_defined(
 ; CHECK-SAME: i8 [[X:%.*]]) {
-; CHECK-NEXT:    [[CTTZ:%.*]] = call range(i8 0, 9) i8 @llvm.cttz.i8(i8 [[X]], i1 false)
-; CHECK-NEXT:    [[RET:%.*]] = call i8 @llvm.umin.i8(i8 [[CTTZ]], i8 6)
+; CHECK-NEXT:    [[TMP1:%.*]] = or i8 [[X]], 64
+; CHECK-NEXT:    [[RET:%.*]] = call range(i8 0, 7) i8 @llvm.cttz.i8(i8 [[TMP1]], i1 true)
 ; CHECK-NEXT:    ret i8 [[RET]]
 ;
   %cttz = call i8 @llvm.cttz.i8(i8 %X, i1 false)
@@ -28,8 +28,8 @@ define i8 @umin_cttz_i8_zero_defined(i8 %X) {
 define i8 @umin_cttz_i8_commuted_zero_undefined(i8 %X) {
 ; CHECK-LABEL: define i8 @umin_cttz_i8_commuted_zero_undefined(
 ; CHECK-SAME: i8 [[X:%.*]]) {
-; CHECK-NEXT:    [[CTTZ:%.*]] = call range(i8 0, 9) i8 @llvm.cttz.i8(i8 [[X]], i1 true)
-; CHECK-NEXT:    [[RET:%.*]] = call i8 @llvm.umin.i8(i8 [[CTTZ]], i8 6)
+; CHECK-NEXT:    [[TMP1:%.*]] = or i8 [[X]], 64
+; CHECK-NEXT:    [[RET:%.*]] = call range(i8 0, 7) i8 @llvm.cttz.i8(i8 [[TMP1]], i1 true)
 ; CHECK-NEXT:    ret i8 [[RET]]
 ;
   %cttz = call i8 @llvm.cttz.i8(i8 %X, i1 true)
@@ -51,8 +51,8 @@ define i8 @umin_cttz_i8_negative_ge_bitwidth_zero_undefined(i8 %X) {
 define i16 @umin_cttz_i16_zero_undefined(i16 %X) {
 ; CHECK-LABEL: define i16 @umin_cttz_i16_zero_undefined(
 ; CHECK-SAME: i16 [[X:%.*]]) {
-; CHECK-NEXT:    [[CTTZ:%.*]] = call range(i16 0, 17) i16 @llvm.cttz.i16(i16 [[X]], i1 true)
-; CHECK-NEXT:    [[RET:%.*]] = call i16 @llvm.umin.i16(i16 [[CTTZ]], i16 6)
+; CHECK-NEXT:    [[TMP1:%.*]] = or i16 [[X]], 64
+; CHECK-NEXT:    [[RET:%.*]] = call range(i16 0, 7) i16 @llvm.cttz.i16(i16 [[TMP1]], i1 true)
 ; CHECK-NEXT:    ret i16 [[RET]]
 ;
   %cttz = call i16 @llvm.cttz.i16(i16 %X, i1 true)
@@ -63,8 +63,8 @@ define i16 @umin_cttz_i16_zero_undefined(i16 %X) {
 define i32 @umin_cttz_i32_zero_undefined(i32 %X) {
 ; CHECK-LABEL: define i32 @umin_cttz_i32_zero_undefined(
 ; CHECK-SAME: i32 [[X:%.*]]) {
-; CHECK-NEXT:    [[CTTZ:%.*]] = call range(i32 0, 33) i32 @llvm.cttz.i32(i32 [[X]], i1 true)
-; CHECK-NEXT:    [[RET:%.*]] = call i32 @llvm.umin.i32(i32 [[CTTZ]], i32 6)
+; CHECK-NEXT:    [[TMP1:%.*]] = or i32 [[X]], 64
+; CHECK-NEXT:    [[RET:%.*]] = call range(i32 0, 7) i32 @llvm.cttz.i32(i32 [[TMP1]], i1 true)
 ; CHECK-NEXT:    ret i32 [[RET]]
 ;
   %cttz = call i32 @llvm.cttz.i32(i32 %X, i1 true)
@@ -75,8 +75,8 @@ define i32 @umin_cttz_i32_zero_undefined(i32 %X) {
 define i64 @umin_cttz_i64_zero_undefined(i64 %X) {
 ; CHECK-LABEL: define i64 @umin_cttz_i64_zero_undefined(
 ; CHECK-SAME: i64 [[X:%.*]]) {
-; CHECK-NEXT:    [[CTTZ:%.*]] = call range(i64 0, 65) i64 @llvm.cttz.i64(i64 [[X]], i1 true)
-; CHECK-NEXT:    [[RET:%.*]] = call i64 @llvm.umin.i64(i64 [[CTTZ]], i64 6)
+; CHECK-NEXT:    [[TMP1:%.*]] = or i64 [[X]], 64
+; CHECK-NEXT:    [[RET:%.*]] = call range(i64 0, 7) i64 @llvm.cttz.i64(i64 [[TMP1]], i1 true)
 ; CHECK-NEXT:    ret i64 [[RET]]
 ;
   %cttz = call i64 @llvm.cttz.i64(i64 %X, i1 true)
@@ -108,8 +108,8 @@ define i1 @umin_cttz_i1_zero_defined(i1 %X) {
 define <2 x i32> @umin_cttz_2xi32_splat_zero_undefined(<2 x i32> %X) {
 ; CHECK-LABEL: define <2 x i32> @umin_cttz_2xi32_splat_zero_undefined(
 ; CHECK-SAME: <2 x i32> [[X:%.*]]) {
-; CHECK-NEXT:    [[CTTZ:%.*]] = call range(i32 0, 33) <2 x i32> @llvm.cttz.v2i32(<2 x i32> [[X]], i1 true)
-; CHECK-NEXT:    [[RET:%.*]] = call <2 x i32> @llvm.umin.v2i32(<2 x i32> [[CTTZ]], <2 x i32> <i32 6, i32 6>)
+; CHECK-NEXT:    [[TMP1:%.*]] = or <2 x i32> [[X]], <i32 64, i32 64>
+; CHECK-NEXT:    [[RET:%.*]] = call range(i32 0, 7) <2 x i32> @llvm.cttz.v2i32(<2 x i32> [[TMP1]], i1 true)
 ; CHECK-NEXT:    ret <2 x i32> [[RET]]
 ;
   %cttz = call <2 x i32> @llvm.cttz.v2i32(<2 x i32> %X, i1 true)
@@ -120,8 +120,8 @@ define <2 x i32> @umin_cttz_2xi32_splat_zero_undefined(<2 x i32> %X) {
 define <2 x i32> @umin_cttz_2xi32_splat_poison_zero_undefined(<2 x i32> %X) {
 ; CHECK-LABEL: define <2 x i32> @umin_cttz_2xi32_splat_poison_zero_undefined(
 ; CHECK-SAME: <2 x i32> [[X:%.*]]) {
-; CHECK-NEXT:    [[CTTZ:%.*]] = call range(i32 0, 33) <2 x i32> @llvm.cttz.v2i32(<2 x i32> [[X]], i1 true)
-; CHECK-NEXT:    [[RET:%.*]] = call <2 x i32> @llvm.umin.v2i32(<2 x i32> [[CTTZ]], <2 x i32> <i32 6, i32 poison>)
+; CHECK-NEXT:    [[TMP1:%.*]] = or <2 x i32> [[X]], <i32 64, i32 poison>
+; CHECK-NEXT:    [[RET:%.*]] = call range(i32 0, 7) <2 x i32> @llvm.cttz.v2i32(<2 x i32> [[TMP1]], i1 true)
 ; CHECK-NEXT:    ret <2 x i32> [[RET]]
 ;
   %cttz = call <2 x i32> @llvm.cttz.v2i32(<2 x i32> %X, i1 true)
@@ -132,8 +132,8 @@ define <2 x i32> @umin_cttz_2xi32_splat_poison_zero_undefined(<2 x i32> %X) {
 define <2 x i32> @umin_cttz_2xi32_no_splat_all_lt_bitwidth_zero_undefined(<2 x i32> %X) {
 ; CHECK-LABEL: define <2 x i32> @umin_cttz_2xi32_no_splat_all_lt_bitwidth_zero_undefined(
 ; CHECK-SAME: <2 x i32> [[X:%.*]]) {
-; CHECK-NEXT:    [[CTTZ:%.*]] = call range(i32 0, 33) <2 x i32> @llvm.cttz.v2i32(<2 x i32> [[X]], i1 true)
-; CHECK-NEXT:    [[RET:%.*]] = call <2 x i32> @llvm.umin.v2i32(<2 x i32> [[CTTZ]], <2 x i32> <i32 6, i32 0>)
+; CHECK-NEXT:    [[TMP1:%.*]] = or <2 x i32> [[X]], <i32 64, i32 1>
+; CHECK-NEXT:    [[RET:%.*]] = call range(i32 0, 33) <2 x i32> @llvm.cttz.v2i32(<2 x i32> [[TMP1]], i1 true)
 ; CHECK-NEXT:    ret <2 x i32> [[RET]]
 ;
   %cttz = call <2 x i32> @llvm.cttz.v2i32(<2 x i32> %X, i1 true)
@@ -144,9 +144,9 @@ define <2 x i32> @umin_cttz_2xi32_no_splat_all_lt_bitwidth_zero_undefined(<2 x i
 define <2 x i32> @umin_cttz_2xi32_negative_no_splat_some_lt_bitwidth_zero_undefined(<2 x i32> %X) {
 ; CHECK-LABEL: define <2 x i32> @umin_cttz_2xi32_negative_no_splat_some_lt_bitwidth_zero_undefined(
 ; CHECK-SAME: <2 x i32> [[X:%.*]]) {
-; CHECK-NEXT:    [[CTTZ:%.*]] = call range(i32 0, 33) <2 x i32> @llvm.cttz.v2i32(<2 x i32> [[X]], i1 true)
-; CHECK-NEXT:    [[RET:%.*]] = call <2 x i32> @llvm.umin.v2i32(<2 x i32> [[CTTZ]], <2 x i32> <i32 6, i32 64>)
-; CHECK-NEXT:    ret <2 x i32> [[RET]]
+; CHECK-NEXT:    [[RET:%.*]] = call range(i32 0, 33) <2 x i32> @llvm.cttz.v2i32(<2 x i32> [[X]], i1 true)
+; CHECK-NEXT:    [[RET1:%.*]] = call <2 x i32> @llvm.umin.v2i32(<2 x i32> [[RET]], <2 x i32> <i32 6, i32 64>)
+; CHECK-NEXT:    ret <2 x i32> [[RET1]]
 ;
   %cttz = call <2 x i32> @llvm.cttz.v2i32(<2 x i32> %X, i1 true)
   %ret = call <2 x i32> @llvm.umin.v2i32(<2 x i32> %cttz, <2 x i32> <i32 6, i32 64>)
@@ -156,9 +156,9 @@ define <2 x i32> @umin_cttz_2xi32_negative_no_splat_some_lt_bitwidth_zero_undefi
 define <2 x i32> @umin_cttz_2xi32_negative_no_splat_none_lt_bitwidth_zero_undefined(<2 x i32> %X) {
 ; CHECK-LABEL: define <2 x i32> @umin_cttz_2xi32_negative_no_splat_none_lt_bitwidth_zero_undefined(
 ; CHECK-SAME: <2 x i32> [[X:%.*]]) {
-; CHECK-NEXT:    [[CTTZ:%.*]] = call range(i32 0, 33) <2 x i32> @llvm.cttz.v2i32(<2 x i32> [[X]], i1 true)
-; CHECK-NEXT:    [[RET:%.*]] = call <2 x i32> @llvm.umin.v2i32(<2 x i32> [[CTTZ]], <2 x i32> <i32 32, i32 64>)
-; CHECK-NEXT:    ret <2 x i32> [[RET]]
+; CHECK-NEXT:    [[RET:%.*]] = call range(i32 0, 33) <2 x i32> @llvm.cttz.v2i32(<2 x i32> [[X]], i1 true)
+; CHECK-NEXT:    [[RET1:%.*]] = call <2 x i32> @llvm.umin.v2i32(<2 x i32> [[RET]], <2 x i32> <i32 32, i32 64>)
+; CHECK-NEXT:    ret <2 x i32> [[RET1]]
 ;
   %cttz = call <2 x i32> @llvm.cttz.v2i32(<2 x i32> %X, i1 true)
   %ret = call <2 x i32> @llvm.umin.v2i32(<2 x i32> %cttz, <2 x i32> <i32 32, i32 64>)
@@ -194,8 +194,8 @@ define i16 @umin_cttz_i16_negative_two_uses(i16 %X) {
 define i8 @umin_ctlz_i8_zero_undefined(i8 %X) {
 ; CHECK-LABEL: define i8 @umin_ctlz_i8_zero_undefined(
 ; CHECK-SAME: i8 [[X:%.*]]) {
-; CHECK-NEXT:    [[CTLZ:%.*]] = call range(i8 0, 9) i8 @llvm.ctlz.i8(i8 [[X]], i1 true)
-; CHECK-NEXT:    [[RET:%.*]] = call i8 @llvm.umin.i8(i8 [[CTLZ]], i8 6)
+; CHECK-NEXT:    [[TMP1:%.*]] = or i8 [[X]], 2
+; CHECK-NEXT:    [[RET:%.*]] = call range(i8 0, 7) i8 @llvm.ctlz.i8(i8 [[TMP1]], i1 true)
 ; CHECK-NEXT:    ret i8 [[RET]]
 ;
   %ctlz = call i8 @llvm.ctlz.i8(i8 %X, i1 true)
@@ -206,8 +206,8 @@ define i8 @umin_ctlz_i8_zero_undefined(i8 %X) {
 define i8 @umin_ctlz_i8_zero_defined(i8 %X) {
 ; CHECK-LABEL: define i8 @umin_ctlz_i8_zero_defined(
 ; CHECK-SAME: i8 [[X:%.*]]) {
-; CHECK-NEXT:    [[CTLZ:%.*]] = call range(i8 0, 9) i8 @llvm.ctlz.i8(i8 [[X]], i1 false)
-; CHECK-NEXT:    [[RET:%.*]] = call i8 @llvm.umin.i8(i8 [[CTLZ]], i8 6)
+; CHECK-NEXT:    [[TMP1:%.*]] = or i8 [[X]], 2
+; CHECK-NEXT:    [[RET:%.*]] = call range(i8 0, 7) i8 @llvm.ctlz.i8(i8 [[TMP1]], i1 true)
 ; CHECK-NEXT:    ret i8 [[RET]]
 ;
   %ctlz = call i8 @llvm.ctlz.i8(i8 %X, i1 false)
@@ -218,8 +218,8 @@ define i8 @umin_ctlz_i8_zero_defined(i8 %X) {
 define i8 @umin_ctlz_i8_commuted_zero_undefined(i8 %X) {
 ; CHECK-LABEL: define i8 @umin_ctlz_i8_commuted_zero_undefined(
 ; CHECK-SAME: i8 [[X:%.*]]) {
-; CHECK-NEXT:    [[CTLZ:%.*]] = call range(i8 0, 9) i8 @llvm.ctlz.i8(i8 [[X]], i1 true)
-; CHECK-NEXT:    [[RET:%.*]] = call i8 @llvm.umin.i8(i8 [[CTLZ]], i8 6)
+; CHECK-NEXT:    [[TMP1:%.*]] = or i8 [[X]], 2
+; CHECK-NEXT:    [[RET:%.*]] = call range(i8 0, 7) i8 @llvm.ctlz.i8(i8 [[TMP1]], i1 true)
 ; CHECK-NEXT:    ret i8 [[RET]]
 ;
   %ctlz = call i8 @llvm.ctlz.i8(i8 %X, i1 true)
@@ -241,8 +241,8 @@ define i8 @umin_ctlz_i8_negative_ge_bitwidth_zero_undefined(i8 %X) {
 define i16 @umin_ctlz_i16_zero_undefined(i16 %X) {
 ; CHECK-LABEL: define i16 @umin_ctlz_i16_zero_undefined(
 ; CHECK-SAME: i16 [[X:%.*]]) {
-; CHECK-NEXT:    [[CTLZ:%.*]] = call range(i16 0, 17) i16 @llvm.ctlz.i16(i16 [[X]], i1 true)
-; CHECK-NEXT:    [[RET:%.*]] = call i16 @llvm.umin.i16(i16 [[CTLZ]], i16 6)
+; CHECK-NEXT:    [[TMP1:%.*]] = or i16 [[X]], 512
+; CHECK-NEXT:    [[RET:%.*]] = call range(i16 0, 7) i16 @llvm.ctlz.i16(i16 [[TMP1]], i1 true)
 ; CHECK-NEXT:    ret i16 [[RET]]
 ;
   %ctlz = call i16 @llvm.ctlz.i16(i16 %X, i1 true)
@@ -253,8 +253,8 @@ define i16 @umin_ctlz_i16_zero_undefined(i16 %X) {
 define i32 @umin_ctlz_i32_zero_undefined(i32 %X) {
 ; CHECK-LABEL: define i32 @umin_ctlz_i32_zero_undefined(
 ; CHECK-SAME: i32 [[X:%.*]]) {
-; CHECK-NEXT:    [[CTLZ:%.*]] = call range(i32 0, 33) i32 @llvm.ctlz.i32(i32 [[X]], i1 true)
-; CHECK-NEXT:    [[RET:%.*]] = call i32 @llvm.umin.i32(i32 [[CTLZ]], i32 6)
+; CHECK-NEXT:    [[TMP1:%.*]] = or i32 [[X]], 33554432
+; CHECK-NEXT:    [[RET:%.*]] = call range(i32 0, 7) i32 @llvm.ctlz.i32(i32 [[TMP1]], i1 true)
 ; CHECK-NEXT:    ret i32 [[RET]]
 ;
   %ctlz = call i32 @llvm.ctlz.i32(i32 %X, i1 true)
@@ -265,8 +265,8 @@ define i32 @umin_ctlz_i32_zero_undefined(i32 %X) {
 define i64 @umin_ctlz_i64_zero_undefined(i64 %X) {
 ; CHECK-LABEL: define i64 @umin_ctlz_i64_zero_undefined(
 ; CHECK-SAME: i64 [[X:%.*]]) {
-; CHECK-NEXT:    [[CTLZ:%.*]] = call range(i64 0, 65) i64 @llvm.ctlz.i64(i64 [[X]], i1 true)
-; CHECK-NEXT:    [[RET:%.*]] = call i64 @llvm.umin.i64(i64 [[CTLZ]], i64 6)
+; CHECK-NEXT:    [[TMP1:%.*]] = or i64 [[X]], 144115188075855872
+; CHECK-NEXT:    [[RET:%.*]] = call range(i64 0, 7) i64 @llvm.ctlz.i64(i64 [[TMP1]], i1 true)
 ; CHECK-NEXT:    ret i64 [[RET]]
 ;
   %ctlz = call i64 @llvm.ctlz.i64(i64 %X, i1 true)
@@ -298,8 +298,8 @@ define i1 @umin_ctlz_i1_zero_defined(i1 %X) {
 define <2 x i32> @umin_ctlz_2xi32_splat_zero_undefined(<2 x i32> %X) {
 ; CHECK-LABEL: define <2 x i32> @umin_ctlz_2xi32_splat_zero_undefined(
 ; CHECK-SAME: <2 x i32> [[X:%.*]]) {
-; CHECK-NEXT:    [[CTLZ:%.*]] = call range(i32 0, 33) <2 x i32> @llvm.ctlz.v2i32(<2 x i32> [[X]], i1 true)
-; CHECK-NEXT:    [[RET:%.*]] = call <2 x i32> @llvm.umin.v2i32(<2 x i32> [[CTLZ]], <2 x i32> <i32 6, i32 6>)
+; CHECK-NEXT:    [[TMP1:%.*]] = or <2 x i32> [[X]], <i32 33554432, i32 33554432>
+; CHECK-NEXT:    [[RET:%.*]] = call range(i32 0, 7) <2 x i32> @llvm.ctlz.v2i32(<2 x i32> [[TMP1]], i1 true)
 ; CHECK-NEXT:    ret <2 x i32> [[RET]]
 ;
   %ctlz = call <2 x i32> @llvm.ctlz.v2i32(<2 x i32> %X, i1 true)
@@ -310,8 +310,8 @@ define <2 x i32> @umin_ctlz_2xi32_splat_zero_undefined(<2 x i32> %X) {
 define <2 x i32> @umin_ctlz_2xi32_splat_poison_zero_undefined(<2 x i32> %X) {
 ; CHECK-LABEL: define <2 x i32> @umin_ctlz_2xi32_splat_poison_zero_undefined(
 ; CHECK-SAME: <2 x i32> [[X:%.*]]) {
-; CHECK-NEXT:    [[CTLZ:%.*]] = call range(i32 0, 33) <2 x i32> @llvm.ctlz.v2i32(<2 x i32> [[X]], i1 true)
-; CHECK-NEXT:    [[RET:%.*]] = call <2 x i32> @llvm.umin.v2i32(<2 x i32> [[CTLZ]], <2 x i32> <i32 6, i32 poison>)
+; CHECK-NEXT:    [[TMP1:%.*]] = or <2 x i32> [[X]], <i32 33554432, i32 poison>
+; CHECK-NEXT:    [[RET:%.*]] = call range(i32 0, 7) <2 x i32> @llvm.ctlz.v2i32(<2 x i32> [[TMP1]], i1 true)
 ; CHECK-NEXT:    ret <2 x i32> [[RET]]
 ;
   %ctlz = call <2 x i32> @llvm.ctlz.v2i32(<2 x i32> %X, i1 true)
@@ -322,8 +322,8 @@ define <2 x i32> @umin_ctlz_2xi32_splat_poison_zero_undefined(<2 x i32> %X) {
 define <2 x i32> @umin_ctlz_2xi32_no_splat_all_lt_bitwidth_zero_undefined(<2 x i32> %X) {
 ; CHECK-LABEL: define <2 x i32> @umin_ctlz_2xi32_no_splat_all_lt_bitwidth_zero_undefined(
 ; CHECK-SAME: <2 x i32> [[X:%.*]]) {
-; CHECK-NEXT:    [[CTLZ:%.*]] = call range(i32 0, 33) <2 x i32> @llvm.ctlz.v2i32(<2 x i32> [[X]], i1 true)
-; CHECK-NEXT:    [[RET:%.*]] = call <2 x i32> @llvm.umin.v2i32(<2 x i32> [[CTLZ]], <2 x i32> <i32 6, i32 0>)
+; CHECK-NEXT:    [[TMP1:%.*]] = or <2 x i32> [[X]], <i32 33554432, i32 -2147483648>
+; CHECK-NEXT:    [[RET:%.*]] = call range(i32 0, 33) <2 x i32> @llvm.ctlz.v2i32(<2 x i32> [[TMP1]], i1 true)
 ; CHECK-NEXT:    ret <2 x i32> [[RET]]
 ;
   %ctlz = call <2 x i32> @llvm.ctlz.v2i32(<2 x i32> %X, i1 true)
@@ -334,9 +334,9 @@ define <2 x i32> @umin_ctlz_2xi32_no_splat_all_lt_bitwidth_zero_undefined(<2 x i
 define <2 x i32> @umin_ctlz_2xi32_negative_no_splat_some_lt_bitwidth_zero_undefined(<2 x i32> %X) {
 ; CHECK-LABEL: define <2 x i32> @umin_ctlz_2xi32_negative_no_splat_some_lt_bitwidth_zero_undefined(
 ; CHECK-SAME: <2 x i32> [[X:%.*]]) {
-; CHECK-NEXT:    [[CTLZ:%.*]] = call range(i32 0, 33) <2 x i32> @llvm.ctlz.v2i32(<2 x i32> [[X]], i1 true)
-; CHECK-NEXT:    [[RET:%.*]] = call <2 x i32> @llvm.umin.v2i32(<2 x i32> [[CTLZ]], <2 x i32> <i32 6, i32 64>)
-; CHECK-NEXT:    ret <2 x i32> [[RET]]
+; CHECK-NEXT:    [[RET:%.*]] = call range(i32 0, 33) <2 x i32> @llvm.ctlz.v2i32(<2 x i32> [[X]], i1 true)
+; CHECK-NEXT:    [[RET1:%.*]] = call <2 x i32> @llvm.umin.v2i32(<2 x i32> [[RET]], <2 x i32> <i32 6, i32 64>)
+; CHECK-NEXT:    ret <2 x i32> [[RET1]]
 ;
   %ctlz = call <2 x i32> @llvm.ctlz.v2i32(<2 x i32> %X, i1 true)
   %ret = call <2 x i32> @llvm.umin.v2i32(<2 x i32> %ctlz, <2 x i32> <i32 6, i32 64>)
@@ -346,9 +346,9 @@ define <2 x i32> @umin_ctlz_2xi32_negative_no_splat_some_lt_bitwidth_zero_undefi
 define <2 x i32> @umin_ctlz_2xi32_negative_no_splat_none_lt_bitwidth_zero_undefined(<2 x i32> %X) {
 ; CHECK-LABEL: define <2 x i32> @umin_ctlz_2xi32_negative_no_splat_none_lt_bitwidth_zero_undefined(
 ; CHECK-SAME: <2 x i32> [[X:%.*]]) {
-; CHECK-NEXT:    [[CTLZ:%.*]] = call range(i32 0, 33) <2 x i32> @llvm.ctlz.v2i32(<2 x i32> [[X]], i1 true)
-; CHECK-NEXT:    [[RET:%.*]] = call <2 x i32> @llvm.umin.v2i32(<2 x i32> [[CTLZ]], <2 x i32> <i32 32, i32 64>)
-; CHECK-NEXT:    ret <2 x i32> [[RET]]
+; CHECK-NEXT:    [[RET:%.*]] = call range(i32 0, 33) <2 x i32> @llvm.ctlz.v2i32(<2 x i32> [[X]], i1 true)
+; CHECK-NEXT:    [[RET1:%.*]] = call <2 x i32> @llvm.umin.v2i32(<2 x i32> [[RET]], <2 x i32> <i32 32, i32 64>)
+; CHECK-NEXT:    ret <2 x i32> [[RET1]]
 ;
   %ctlz = call <2 x i32> @llvm.ctlz.v2i32(<2 x i32> %X, i1 true)
   %ret = call <2 x i32> @llvm.umin.v2i32(<2 x i32> %ctlz, <2 x i32> <i32 32, i32 64>)



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