[lanai] Add computeKnownBitsForTargetNode for Lanai.

Summary: computeKnownBitsForTargetNode was not defined for Lanai which resulted in additional AND's with 0x1 for the output of SETCC instructions.

Reviewers: eliben, majnemer

Reviewed By: majnemer

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D29605

llvm-svn: 302568

1 files changed, 48 insertions, 0 deletions

diff --git a/llvm/test/CodeGen/Lanai/masking_setccs.ll b/llvm/test/CodeGen/Lanai/masking_setccs.ll
new file mode 100644
index 00000000000..48136fd4257
--- /dev/null
+++ b/llvm/test/CodeGen/Lanai/masking_setccs.ll
@@ -0,0 +1,48 @@
+; RUN: llc < %s | FileCheck %s
+
+; Test that unnecessary masking with 0x1 is not inserted.
+
+target datalayout = "E-m:e-p:32:32-i64:64-a:0:32-n32-S64"
+target triple = "lanai"
+
+; CHECK-LABEL: masking:
+; CHECK-NOT: mov 1
+define i32 @masking(i32 inreg %a, i32 inreg %b, i32 inreg %c, i32 inreg %d) {
+entry:
+  %cmp = icmp ne i32 %a, 0
+  %cmp1 = icmp ult i32 %a, %b
+  %or.cond = and i1 %cmp, %cmp1
+  br i1 %or.cond, label %return, label %if.end
+
+if.end:                                           ; preds = %entry
+  %cmp2 = icmp ne i32 %b, 0
+  %cmp4 = icmp ult i32 %b, %c
+  %or.cond29 = and i1 %cmp2, %cmp4
+  br i1 %or.cond29, label %return, label %if.end6
+
+if.end6:                                          ; preds = %if.end
+  %cmp7 = icmp ne i32 %c, 0
+  %cmp9 = icmp ult i32 %c, %d
+  %or.cond30 = and i1 %cmp7, %cmp9
+  br i1 %or.cond30, label %return, label %if.end11
+
+if.end11:                                         ; preds = %if.end6
+  %cmp12 = icmp ne i32 %d, 0
+  %cmp14 = icmp ult i32 %d, %a
+  %or.cond31 = and i1 %cmp12, %cmp14
+  %b. = select i1 %or.cond31, i32 %b, i32 21
+  ret i32 %b.
+
+return:                                           ; preds = %if.end6, %if.end, %entry
+  %retval.0 = phi i32 [ %c, %entry ], [ %d, %if.end ], [ %a, %if.end6 ]
+  ret i32 %retval.0
+}
+
+; CHECK-LABEL: notnot:
+; CHECK-NOT: mov 1
+define i32 @notnot(i32 %x) {
+entry:
+  %tobool = icmp ne i32 %x, 0
+  %lnot.ext = zext i1 %tobool to i32
+  ret i32 %lnot.ext
+}