[X86] AMD Zen 3: same-reg SSE XMM PXOR is a 1-cycle(!) dep-breaking zero-idiom

As confirmed by the exegesis measurements, and ref docs.
This commit is contained in:
Roman Lebedev 2021-05-14 15:44:32 +03:00
parent 3009f8a383
commit 498bf365f4
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GPG Key ID: 083C3EBB4A1689E0
2 changed files with 25 additions and 19 deletions

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@ -1553,8 +1553,14 @@ def : IsZeroIdiomFunction<[
SUB64rr, SUB64rr_REV ], ZeroIdiomPredicate>,
// SSE XMM Zero-idioms.
DepBreakingClass<[ XORPSrr, XORPDrr,
ANDNPSrr, ANDNPDrr ], ZeroIdiomPredicate>,
DepBreakingClass<[
// fp variants.
XORPSrr, XORPDrr,
ANDNPSrr, ANDNPDrr,
// int variants.
PXORrr
], ZeroIdiomPredicate>,
// AVX XMM Zero-idioms.
DepBreakingClass<[ VXORPSrr, VXORPDrr,

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@ -394,12 +394,12 @@ pxor %xmm0, %xmm1
# CHECK: Iterations: 10000
# CHECK-NEXT: Instructions: 20000
# CHECK-NEXT: Total Cycles: 20003
# CHECK-NEXT: Total Cycles: 5004
# CHECK-NEXT: Total uOps: 20000
# CHECK: Dispatch Width: 6
# CHECK-NEXT: uOps Per Cycle: 1.00
# CHECK-NEXT: IPC: 1.00
# CHECK-NEXT: uOps Per Cycle: 4.00
# CHECK-NEXT: IPC: 4.00
# CHECK-NEXT: Block RThroughput: 0.5
# CHECK: Instruction Info:
@ -415,13 +415,13 @@ pxor %xmm0, %xmm1
# CHECK-NEXT: 1 1 0.25 pxor %xmm0, %xmm1
# CHECK: Register File statistics:
# CHECK-NEXT: Total number of mappings created: 20000
# CHECK-NEXT: Max number of mappings used: 66
# CHECK-NEXT: Total number of mappings created: 10000
# CHECK-NEXT: Max number of mappings used: 37
# CHECK: * Register File #1 -- Zn3FpPRF:
# CHECK-NEXT: Number of physical registers: 160
# CHECK-NEXT: Total number of mappings created: 20000
# CHECK-NEXT: Max number of mappings used: 66
# CHECK-NEXT: Total number of mappings created: 10000
# CHECK-NEXT: Max number of mappings used: 37
# CHECK: * Register File #2 -- Zn3IntegerPRF:
# CHECK-NEXT: Number of physical registers: 192
@ -459,16 +459,16 @@ pxor %xmm0, %xmm1
# CHECK: Resource pressure by instruction:
# CHECK-NEXT: [0] [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12.0] [12.1] [13] [14.0] [14.1] [14.2] [15.0] [15.1] [15.2] [16.0] [16.1] Instructions:
# CHECK-NEXT: - - - - - - - - - 0.50 - 0.50 - - - - - - - - - - - pxor %xmm1, %xmm1
# CHECK-NEXT: - - - - - - - - 0.50 - 0.50 - - - - - - - - - - - - pxor %xmm0, %xmm1
# CHECK-NEXT: - - - - - - - - - 0.50 0.25 0.25 - - - - - - - - - - - pxor %xmm1, %xmm1
# CHECK-NEXT: - - - - - - - - 0.50 - 0.25 0.25 - - - - - - - - - - - pxor %xmm0, %xmm1
# CHECK: Timeline view:
# CHECK-NEXT: Index 0123456
# CHECK-NEXT: Index 01234
# CHECK: [0,0] DeER .. pxor %xmm1, %xmm1
# CHECK-NEXT: [0,1] D=eER.. pxor %xmm0, %xmm1
# CHECK-NEXT: [1,0] D==eER. pxor %xmm1, %xmm1
# CHECK-NEXT: [1,1] D===eER pxor %xmm0, %xmm1
# CHECK: [0,0] DeER. pxor %xmm1, %xmm1
# CHECK-NEXT: [0,1] D=eER pxor %xmm0, %xmm1
# CHECK-NEXT: [1,0] DeE-R pxor %xmm1, %xmm1
# CHECK-NEXT: [1,1] D=eER pxor %xmm0, %xmm1
# CHECK: Average Wait times (based on the timeline view):
# CHECK-NEXT: [0]: Executions
@ -477,6 +477,6 @@ pxor %xmm0, %xmm1
# CHECK-NEXT: [3]: Average time elapsed from WB until retire stage
# CHECK: [0] [1] [2] [3]
# CHECK-NEXT: 0. 2 2.0 0.5 0.0 pxor %xmm1, %xmm1
# CHECK-NEXT: 1. 2 3.0 0.0 0.0 pxor %xmm0, %xmm1
# CHECK-NEXT: 2 2.5 0.3 0.0 <total>
# CHECK-NEXT: 0. 2 1.0 1.0 0.5 pxor %xmm1, %xmm1
# CHECK-NEXT: 1. 2 2.0 0.0 0.0 pxor %xmm0, %xmm1
# CHECK-NEXT: 2 1.5 0.5 0.3 <total>