[llvm] 3e6b80b - [CSKY] Optimize conditional select with CLRT/CLRF

[Ben Shi via llvm-commits]

Author: Ben Shi
Date: 2023-07-04T15:22:18+08:00
New Revision: 3e6b80b1bdf42d7f3c73541250b2eb2480e7df32

URL: https://github.com/llvm/llvm-project/commit/3e6b80b1bdf42d7f3c73541250b2eb2480e7df32
DIFF: https://github.com/llvm/llvm-project/commit/3e6b80b1bdf42d7f3c73541250b2eb2480e7df32.diff

LOG: [CSKY] Optimize conditional select with CLRT/CLRF

Reviewed By: zixuan-wu

Differential Revision: https://reviews.llvm.org/D154409

Added: 
    

Modified: 
    llvm/lib/Target/CSKY/CSKYInstrInfo.td
    llvm/test/CodeGen/CSKY/select.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Target/CSKY/CSKYInstrInfo.td b/llvm/lib/Target/CSKY/CSKYInstrInfo.td
index 078b4c8cb6084b..549c883c34a729 100644
--- a/llvm/lib/Target/CSKY/CSKYInstrInfo.td
+++ b/llvm/lib/Target/CSKY/CSKYInstrInfo.td
@@ -1410,6 +1410,11 @@ defm : MOVTF32Pat1<setuge, setule, CMPHS32, MOVT32>;
 defm : MOVTF32Pat1<setult, setugt, CMPHS32, MOVF32>;
 defm : MOVTF32Pat1<setlt, setgt, CMPLT32, MOVT32>;
 defm : MOVTF32Pat1<setge, setle, CMPLT32, MOVF32>;
+
+def : Pat<(select CARRY:$ca, (i32 0), GPR:$other),
+          (CLRT32 CARRY:$ca, GPR:$other)>;
+def : Pat<(select CARRY:$ca, GPR:$other, (i32 0)),
+          (CLRF32 CARRY:$ca, GPR:$other)>;
 }
 
 // Constant materialize patterns.

diff  --git a/llvm/test/CodeGen/CSKY/select.ll b/llvm/test/CodeGen/CSKY/select.ll
index eb0bb94e70ec07..a26b1ff113c68b 100644
--- a/llvm/test/CodeGen/CSKY/select.ll
+++ b/llvm/test/CodeGen/CSKY/select.ll
@@ -135,9 +135,8 @@ entry:
 define i32 @selectRI_0_if_true(i1 %c, i32 %q) {
 ; CHECK-LABEL: selectRI_0_if_true:
 ; CHECK:       # %bb.0:
-; CHECK-NEXT:    movi16 a2, 0
 ; CHECK-NEXT:    btsti16 a0, 0
-; CHECK-NEXT:    movt32 a1, a2
+; CHECK-NEXT:    clrt32 a1
 ; CHECK-NEXT:    mov16 a0, a1
 ; CHECK-NEXT:    rts16
 ;
@@ -162,10 +161,9 @@ define i32 @selectRI_0_if_true(i1 %c, i32 %q) {
 define i32 @selectRI_0_if_false(i1 %c, i32 %q) {
 ; CHECK-LABEL: selectRI_0_if_false:
 ; CHECK:       # %bb.0:
-; CHECK-NEXT:    movi16 a2, 0
 ; CHECK-NEXT:    btsti16 a0, 0
-; CHECK-NEXT:    movt32 a2, a1
-; CHECK-NEXT:    mov16 a0, a2
+; CHECK-NEXT:    clrf32 a1
+; CHECK-NEXT:    mov16 a0, a1
 ; CHECK-NEXT:    rts16
 ;
 ; GENERIC-LABEL: selectRI_0_if_false: