1 files changed, 77 insertions, 0 deletions
diff --git a/test/CodeGen/X86/x86-64-double-precision-shift-left.ll b/test/CodeGen/X86/x86-64-double-precision-shift-left.ll
new file mode 100644
index 000000000000..f2380f23b8ee
--- /dev/null
+++ b/test/CodeGen/X86/x86-64-double-precision-shift-left.ll
@@ -0,0 +1,77 @@
+; RUN: llc < %s -march=x86-64 -mcpu=bdver1 | FileCheck %s
+; Verify that for the architectures that are known to have poor latency
+; double precision shift instructions we generate alternative sequence 
+; of instructions with lower latencies instead of shld instruction.
+
+;uint64_t lshift1(uint64_t a, uint64_t b)
+;{
+;    return (a << 1) | (b >> 63);
+;}
+
+; CHECK:             lshift1:
+; CHECK:             addq    {{.*}},{{.*}}
+; CHECK-NEXT:        shrq    $63, {{.*}}
+; CHECK-NEXT:        leaq    ({{.*}},{{.*}}), {{.*}}
+
+
+define i64 @lshift1(i64 %a, i64 %b) nounwind readnone uwtable {
+entry:
+  %shl = shl i64 %a, 1
+  %shr = lshr i64 %b, 63
+  %or = or i64 %shr, %shl
+  ret i64 %or
+}
+
+;uint64_t lshift2(uint64_t a, uint64_t b)
+;{
+;    return (a << 2) | (b >> 62);
+;}
+
+; CHECK:             lshift2:
+; CHECK:             shlq    $2, {{.*}}
+; CHECK-NEXT:        shrq    $62, {{.*}}
+; CHECK-NEXT:        leaq    ({{.*}},{{.*}}), {{.*}}
+
+define i64 @lshift2(i64 %a, i64 %b) nounwind readnone uwtable {
+entry:
+  %shl = shl i64 %a, 2
+  %shr = lshr i64 %b, 62
+  %or = or i64 %shr, %shl
+  ret i64 %or
+}
+
+;uint64_t lshift7(uint64_t a, uint64_t b)
+;{
+;    return (a << 7) | (b >> 57);
+;}
+
+; CHECK:             lshift7:
+; CHECK:             shlq    $7, {{.*}}
+; CHECK-NEXT:        shrq    $57, {{.*}}
+; CHECK-NEXT:        leaq    ({{.*}},{{.*}}), {{.*}}
+
+define i64 @lshift7(i64 %a, i64 %b) nounwind readnone uwtable {
+entry:
+  %shl = shl i64 %a, 7
+  %shr = lshr i64 %b, 57
+  %or = or i64 %shr, %shl
+  ret i64 %or
+}
+
+;uint64_t lshift63(uint64_t a, uint64_t b)
+;{
+;    return (a << 63) | (b >> 1);
+;}
+
+; CHECK:             lshift63:
+; CHECK:             shlq    $63, {{.*}}
+; CHECK-NEXT:        shrq    {{.*}}
+; CHECK-NEXT:        leaq    ({{.*}},{{.*}}), {{.*}}
+
+define i64 @lshift63(i64 %a, i64 %b) nounwind readnone uwtable {
+entry:
+  %shl = shl i64 %a, 63
+  %shr = lshr i64 %b, 1
+  %or = or i64 %shr, %shl
+  ret i64 %or
+}