[llvm] [LICM] Fold associative binary ops to promote code hoisting (PR #81608)
Chen Zheng via llvm-commits
llvm-commits at lists.llvm.org
Mon Feb 19 17:27:09 PST 2024
================
@@ -743,214 +743,219 @@ define signext i32 @spill_reduce_succ(ptr %input1, ptr %input2, ptr %output, i64
; CHECK-NEXT: std r9, -184(r1) # 8-byte Folded Spill
; CHECK-NEXT: std r8, -176(r1) # 8-byte Folded Spill
; CHECK-NEXT: std r7, -168(r1) # 8-byte Folded Spill
-; CHECK-NEXT: std r3, -160(r1) # 8-byte Folded Spill
+; CHECK-NEXT: std r4, -160(r1) # 8-byte Folded Spill
; CHECK-NEXT: ble cr0, .LBB7_7
; CHECK-NEXT: # %bb.1: # %for.body.preheader
-; CHECK-NEXT: sldi r6, r6, 2
-; CHECK-NEXT: li r7, 1
-; CHECK-NEXT: mr r30, r10
-; CHECK-NEXT: cmpdi r6, 1
-; CHECK-NEXT: iselgt r7, r6, r7
-; CHECK-NEXT: addi r8, r7, -1
-; CHECK-NEXT: clrldi r6, r7, 63
-; CHECK-NEXT: cmpldi r8, 3
+; CHECK-NEXT: sldi r4, r6, 2
+; CHECK-NEXT: li r6, 1
+; CHECK-NEXT: mr r0, r10
+; CHECK-NEXT: std r10, -192(r1) # 8-byte Folded Spill
+; CHECK-NEXT: cmpdi r4, 1
+; CHECK-NEXT: iselgt r4, r4, r6
+; CHECK-NEXT: addi r7, r4, -1
+; CHECK-NEXT: clrldi r6, r4, 63
+; CHECK-NEXT: cmpldi r7, 3
; CHECK-NEXT: blt cr0, .LBB7_4
; CHECK-NEXT: # %bb.2: # %for.body.preheader.new
-; CHECK-NEXT: ld r14, -168(r1) # 8-byte Folded Reload
-; CHECK-NEXT: mulli r24, r30, 24
-; CHECK-NEXT: ld r16, -184(r1) # 8-byte Folded Reload
-; CHECK-NEXT: ld r15, -176(r1) # 8-byte Folded Reload
-; CHECK-NEXT: ld r3, -160(r1) # 8-byte Folded Reload
-; CHECK-NEXT: rldicl r0, r7, 62, 2
-; CHECK-NEXT: sldi r11, r30, 5
-; CHECK-NEXT: sldi r19, r30, 4
-; CHECK-NEXT: sldi r7, r14, 3
-; CHECK-NEXT: add r14, r30, r14
-; CHECK-NEXT: sldi r10, r16, 3
-; CHECK-NEXT: sldi r12, r15, 3
-; CHECK-NEXT: add r16, r30, r16
-; CHECK-NEXT: add r15, r30, r15
-; CHECK-NEXT: add r27, r11, r7
-; CHECK-NEXT: add r22, r24, r7
-; CHECK-NEXT: add r17, r19, r7
-; CHECK-NEXT: sldi r2, r14, 3
-; CHECK-NEXT: add r26, r24, r10
-; CHECK-NEXT: add r25, r24, r12
-; CHECK-NEXT: add r21, r19, r10
-; CHECK-NEXT: add r20, r19, r12
-; CHECK-NEXT: add r8, r11, r10
-; CHECK-NEXT: sldi r16, r16, 3
-; CHECK-NEXT: add r29, r5, r27
-; CHECK-NEXT: add r28, r4, r27
-; CHECK-NEXT: add r27, r3, r27
-; CHECK-NEXT: add r24, r5, r22
-; CHECK-NEXT: add r23, r4, r22
-; CHECK-NEXT: add r22, r3, r22
-; CHECK-NEXT: add r19, r5, r17
-; CHECK-NEXT: add r18, r4, r17
-; CHECK-NEXT: add r17, r3, r17
-; CHECK-NEXT: add r14, r5, r2
-; CHECK-NEXT: add r31, r4, r2
-; CHECK-NEXT: add r2, r3, r2
-; CHECK-NEXT: add r9, r5, r8
-; CHECK-NEXT: add r8, r11, r12
-; CHECK-NEXT: add r26, r5, r26
+; CHECK-NEXT: ld r0, -192(r1) # 8-byte Folded Reload
+; CHECK-NEXT: ld r30, -184(r1) # 8-byte Folded Reload
+; CHECK-NEXT: ld r8, -176(r1) # 8-byte Folded Reload
+; CHECK-NEXT: rldicl r7, r4, 62, 2
+; CHECK-NEXT: ld r9, -168(r1) # 8-byte Folded Reload
+; CHECK-NEXT: add r11, r0, r30
+; CHECK-NEXT: add r4, r0, r0
+; CHECK-NEXT: mulli r23, r0, 24
+; CHECK-NEXT: add r14, r0, r8
+; CHECK-NEXT: sldi r12, r0, 5
+; CHECK-NEXT: add r31, r0, r9
+; CHECK-NEXT: sldi r9, r9, 3
+; CHECK-NEXT: sldi r18, r0, 4
+; CHECK-NEXT: sldi r8, r8, 3
+; CHECK-NEXT: add r10, r4, r4
+; CHECK-NEXT: sldi r4, r30, 3
+; CHECK-NEXT: sldi r11, r11, 3
+; CHECK-NEXT: add r26, r12, r9
+; CHECK-NEXT: add r16, r18, r9
+; CHECK-NEXT: add r29, r12, r8
+; CHECK-NEXT: add r19, r18, r8
+; CHECK-NEXT: add r30, r12, r4
+; CHECK-NEXT: mr r20, r4
+; CHECK-NEXT: std r4, -200(r1) # 8-byte Folded Spill
+; CHECK-NEXT: ld r4, -160(r1) # 8-byte Folded Reload
+; CHECK-NEXT: add r15, r5, r11
+; CHECK-NEXT: sldi r11, r14, 3
+; CHECK-NEXT: add r29, r5, r29
+; CHECK-NEXT: add r28, r5, r26
+; CHECK-NEXT: add r19, r5, r19
+; CHECK-NEXT: add r21, r23, r9
+; CHECK-NEXT: add r24, r23, r8
+; CHECK-NEXT: add r14, r5, r11
+; CHECK-NEXT: sldi r11, r31, 3
+; CHECK-NEXT: add r25, r23, r20
+; CHECK-NEXT: add r20, r18, r20
+; CHECK-NEXT: add r30, r5, r30
+; CHECK-NEXT: add r18, r5, r16
+; CHECK-NEXT: add r24, r5, r24
+; CHECK-NEXT: add r23, r5, r21
+; CHECK-NEXT: add r27, r4, r26
+; CHECK-NEXT: add r22, r4, r21
+; CHECK-NEXT: add r17, r4, r16
+; CHECK-NEXT: add r2, r4, r11
+; CHECK-NEXT: rldicl r4, r7, 2, 1
+; CHECK-NEXT: sub r7, r8, r9
+; CHECK-NEXT: ld r8, -200(r1) # 8-byte Folded Reload
+; CHECK-NEXT: add r26, r3, r26
; CHECK-NEXT: add r25, r5, r25
-; CHECK-NEXT: add r21, r5, r21
+; CHECK-NEXT: add r21, r3, r21
; CHECK-NEXT: add r20, r5, r20
-; CHECK-NEXT: add r16, r5, r16
-; CHECK-NEXT: add r8, r5, r8
-; CHECK-NEXT: rldicl r3, r0, 2, 1
-; CHECK-NEXT: addi r3, r3, -4
-; CHECK-NEXT: sub r0, r12, r7
-; CHECK-NEXT: sub r12, r10, r7
-; CHECK-NEXT: li r7, 0
-; CHECK-NEXT: mr r10, r30
-; CHECK-NEXT: sldi r15, r15, 3
-; CHECK-NEXT: add r15, r5, r15
-; CHECK-NEXT: rldicl r3, r3, 62, 2
-; CHECK-NEXT: addi r3, r3, 1
-; CHECK-NEXT: mtctr r3
+; CHECK-NEXT: add r16, r3, r16
+; CHECK-NEXT: add r31, r5, r11
+; CHECK-NEXT: add r11, r3, r11
+; CHECK-NEXT: addi r4, r4, -4
+; CHECK-NEXT: rldicl r4, r4, 62, 2
+; CHECK-NEXT: sub r8, r8, r9
+; CHECK-NEXT: li r9, 0
+; CHECK-NEXT: addi r4, r4, 1
+; CHECK-NEXT: mtctr r4
; CHECK-NEXT: .p2align 4
; CHECK-NEXT: .LBB7_3: # %for.body
; CHECK-NEXT: #
-; CHECK-NEXT: lfd f0, 0(r2)
-; CHECK-NEXT: lfd f1, 0(r31)
-; CHECK-NEXT: add r3, r10, r30
-; CHECK-NEXT: add r3, r3, r30
+; CHECK-NEXT: lfd f0, 0(r11)
----------------
chenzheng1030 wrote:
This case change seems OK. There is no register spill/reload in the loop `.LBB7_3`(original test point) and no extra register usage either.
https://github.com/llvm/llvm-project/pull/81608
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