[SystemZ] Make use of SUBTRACT HALFWORD

Thanks to Ulrich Weigand for noticing that this instruction was missing.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181893 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 131 insertions, 0 deletions

diff --git a/test/CodeGen/SystemZ/int-sub-07.ll b/test/CodeGen/SystemZ/int-sub-07.ll
new file mode 100644
index 0000000..9bf5ed9
--- /dev/null
+++ b/test/CodeGen/SystemZ/int-sub-07.ll
@@ -0,0 +1,131 @@
+; Test 32-bit subtraction in which the second operand is a sign-extended
+; i16 memory value.
+;
+; RUN: llc < %s -mtriple=s390x-linux-gnu | FileCheck %s
+
+; Check the low end of the SH range.
+define i32 @f1(i32 %lhs, i16 *%src) {
+; CHECK: f1:
+; CHECK: sh %r2, 0(%r3)
+; CHECK: br %r14
+  %half = load i16 *%src
+  %rhs = sext i16 %half to i32
+  %res = sub i32 %lhs, %rhs
+  ret i32 %res
+}
+
+; Check the high end of the aligned SH range.
+define i32 @f2(i32 %lhs, i16 *%src) {
+; CHECK: f2:
+; CHECK: sh %r2, 4094(%r3)
+; CHECK: br %r14
+  %ptr = getelementptr i16 *%src, i64 2047
+  %half = load i16 *%ptr
+  %rhs = sext i16 %half to i32
+  %res = sub i32 %lhs, %rhs
+  ret i32 %res
+}
+
+; Check the next halfword up, which should use SHY instead of SH.
+define i32 @f3(i32 %lhs, i16 *%src) {
+; CHECK: f3:
+; CHECK: shy %r2, 4096(%r3)
+; CHECK: br %r14
+  %ptr = getelementptr i16 *%src, i64 2048
+  %half = load i16 *%ptr
+  %rhs = sext i16 %half to i32
+  %res = sub i32 %lhs, %rhs
+  ret i32 %res
+}
+
+; Check the high end of the aligned SHY range.
+define i32 @f4(i32 %lhs, i16 *%src) {
+; CHECK: f4:
+; CHECK: shy %r2, 524286(%r3)
+; CHECK: br %r14
+  %ptr = getelementptr i16 *%src, i64 262143
+  %half = load i16 *%ptr
+  %rhs = sext i16 %half to i32
+  %res = sub i32 %lhs, %rhs
+  ret i32 %res
+}
+
+; Check the next halfword up, which needs separate address logic.
+; Other sequences besides this one would be OK.
+define i32 @f5(i32 %lhs, i16 *%src) {
+; CHECK: f5:
+; CHECK: agfi %r3, 524288
+; CHECK: sh %r2, 0(%r3)
+; CHECK: br %r14
+  %ptr = getelementptr i16 *%src, i64 262144
+  %half = load i16 *%ptr
+  %rhs = sext i16 %half to i32
+  %res = sub i32 %lhs, %rhs
+  ret i32 %res
+}
+
+; Check the high end of the negative aligned SHY range.
+define i32 @f6(i32 %lhs, i16 *%src) {
+; CHECK: f6:
+; CHECK: shy %r2, -2(%r3)
+; CHECK: br %r14
+  %ptr = getelementptr i16 *%src, i64 -1
+  %half = load i16 *%ptr
+  %rhs = sext i16 %half to i32
+  %res = sub i32 %lhs, %rhs
+  ret i32 %res
+}
+
+; Check the low end of the SHY range.
+define i32 @f7(i32 %lhs, i16 *%src) {
+; CHECK: f7:
+; CHECK: shy %r2, -524288(%r3)
+; CHECK: br %r14
+  %ptr = getelementptr i16 *%src, i64 -262144
+  %half = load i16 *%ptr
+  %rhs = sext i16 %half to i32
+  %res = sub i32 %lhs, %rhs
+  ret i32 %res
+}
+
+; Check the next halfword down, which needs separate address logic.
+; Other sequences besides this one would be OK.
+define i32 @f8(i32 %lhs, i16 *%src) {
+; CHECK: f8:
+; CHECK: agfi %r3, -524290
+; CHECK: sh %r2, 0(%r3)
+; CHECK: br %r14
+  %ptr = getelementptr i16 *%src, i64 -262145
+  %half = load i16 *%ptr
+  %rhs = sext i16 %half to i32
+  %res = sub i32 %lhs, %rhs
+  ret i32 %res
+}
+
+; Check that SH allows an index.
+define i32 @f9(i32 %lhs, i64 %src, i64 %index) {
+; CHECK: f9:
+; CHECK: sh %r2, 4094({{%r4,%r3|%r3,%r4}})
+; CHECK: br %r14
+  %sub1 = add i64 %src, %index
+  %sub2 = add i64 %sub1, 4094
+  %ptr = inttoptr i64 %sub2 to i16 *
+  %half = load i16 *%ptr
+  %rhs = sext i16 %half to i32
+  %res = sub i32 %lhs, %rhs
+  ret i32 %res
+}
+
+; Check that SHY allows an index.
+define i32 @f10(i32 %lhs, i64 %src, i64 %index) {
+; CHECK: f10:
+; CHECK: shy %r2, 4096({{%r4,%r3|%r3,%r4}})
+; CHECK: br %r14
+  %sub1 = add i64 %src, %index
+  %sub2 = add i64 %sub1, 4096
+  %ptr = inttoptr i64 %sub2 to i16 *
+  %half = load i16 *%ptr
+  %rhs = sext i16 %half to i32
+  %res = sub i32 %lhs, %rhs
+  ret i32 %res
+}