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[OptimizeInstructions] Canonicalizations for relational ops near signed & unsigned min/max #4282

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Merged
merged 7 commits into from
Aug 27, 2022
Merged

[OptimizeInstructions] Canonicalizations for relational ops near signed & unsigned min/max #4282

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225083a
more canonicalizations for relational ops
MaxGraey Oct 27, 2021
6e89ae6
simplify a little
MaxGraey Oct 27, 2021
3f6783c
fix
MaxGraey Oct 27, 2021
5f1e904
Merge branch 'main' into more-relational-cannon
MaxGraey Jan 27, 2022
1e85f7f
Merge branch 'main' into more-relational-cannon
MaxGraey Aug 26, 2022
ca1f824
use named constants
MaxGraey Aug 26, 2022
fdfffa5
more
MaxGraey Aug 26, 2022
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61 changes: 61 additions & 0 deletions src/passes/OptimizeInstructions.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -2157,6 +2157,67 @@ struct OptimizeInstructions
c->value = Literal::makeZero(c->type);
return;
}
// Prefer compare to signed min (s_min) instead of s_min + 1.
// (signed)x < s_min + 1 ==> x == s_min
if (binary->op == LtSInt32 && c->value.geti32() == INT32_MIN + 1) {
binary->op = EqInt32;
c->value = Literal::makeSignedMin(Type::i32);
return;
}
if (binary->op == LtSInt64 && c->value.geti64() == INT64_MIN + 1) {
binary->op = EqInt64;
c->value = Literal::makeSignedMin(Type::i64);
return;
}
// (signed)x >= s_min + 1 ==> x != s_min
if (binary->op == GeSInt32 && c->value.geti32() == INT32_MIN + 1) {
binary->op = NeInt32;
c->value = Literal::makeSignedMin(Type::i32);
return;
}
if (binary->op == GeSInt64 && c->value.geti64() == INT64_MIN + 1) {
binary->op = NeInt64;
c->value = Literal::makeSignedMin(Type::i64);
return;
}
// Prefer compare to signed max (s_max) instead of s_max - 1.
// (signed)x > s_max - 1 ==> x == s_max
if (binary->op == GtSInt32 && c->value.geti32() == INT32_MAX - 1) {
binary->op = EqInt32;
c->value = Literal::makeSignedMax(Type::i32);
return;
}
if (binary->op == GtSInt64 && c->value.geti64() == INT64_MAX - 1) {
binary->op = EqInt64;
c->value = Literal::makeSignedMax(Type::i64);
return;
}
// (signed)x <= s_max - 1 ==> x != s_max
if (binary->op == LeSInt32 && c->value.geti32() == INT32_MAX - 1) {
binary->op = NeInt32;
c->value = Literal::makeSignedMax(Type::i32);
return;
}
if (binary->op == LeSInt64 && c->value.geti64() == INT64_MAX - 1) {
binary->op = NeInt64;
c->value = Literal::makeSignedMax(Type::i64);
return;
}
// Prefer compare to unsigned max (u_max) instead of u_max - 1.
// (unsigned)x <= u_max - 1 ==> x != u_max
if (binary->op == Abstract::getBinary(c->type, Abstract::LeU) &&
c->value.getInteger() == (int64_t)(UINT64_MAX - 1)) {
binary->op = Abstract::getBinary(c->type, Abstract::Ne);
c->value = Literal::makeUnsignedMax(c->type);
return;
}
// (unsigned)x > u_max - 1 ==> x == u_max
if (binary->op == Abstract::getBinary(c->type, Abstract::GtU) &&
c->value.getInteger() == (int64_t)(UINT64_MAX - 1)) {
binary->op = Abstract::getBinary(c->type, Abstract::Eq);
c->value = Literal::makeUnsignedMax(c->type);
return;
}
return;
}
// Prefer a get on the right.
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130 changes: 130 additions & 0 deletions test/lit/passes/optimize-instructions.wast
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Expand Up @@ -1644,6 +1644,136 @@
(i32.const 1)
))
)
;; CHECK: (func $canonicalize-cmp-near-min-max (param $x i32) (param $y i64)
;; CHECK-NEXT: (drop
;; CHECK-NEXT: (i32.eq
;; CHECK-NEXT: (local.get $x)
;; CHECK-NEXT: (i32.const -2147483648)
;; CHECK-NEXT: )
;; CHECK-NEXT: )
;; CHECK-NEXT: (drop
;; CHECK-NEXT: (i64.eq
;; CHECK-NEXT: (local.get $y)
;; CHECK-NEXT: (i64.const -9223372036854775808)
;; CHECK-NEXT: )
;; CHECK-NEXT: )
;; CHECK-NEXT: (drop
;; CHECK-NEXT: (i32.ne
;; CHECK-NEXT: (local.get $x)
;; CHECK-NEXT: (i32.const -2147483648)
;; CHECK-NEXT: )
;; CHECK-NEXT: )
;; CHECK-NEXT: (drop
;; CHECK-NEXT: (i64.ne
;; CHECK-NEXT: (local.get $y)
;; CHECK-NEXT: (i64.const -9223372036854775808)
;; CHECK-NEXT: )
;; CHECK-NEXT: )
;; CHECK-NEXT: (drop
;; CHECK-NEXT: (i32.eq
;; CHECK-NEXT: (local.get $x)
;; CHECK-NEXT: (i32.const 2147483647)
;; CHECK-NEXT: )
;; CHECK-NEXT: )
;; CHECK-NEXT: (drop
;; CHECK-NEXT: (i64.eq
;; CHECK-NEXT: (local.get $y)
;; CHECK-NEXT: (i64.const 9223372036854775807)
;; CHECK-NEXT: )
;; CHECK-NEXT: )
;; CHECK-NEXT: (drop
;; CHECK-NEXT: (i32.ne
;; CHECK-NEXT: (local.get $x)
;; CHECK-NEXT: (i32.const 2147483647)
;; CHECK-NEXT: )
;; CHECK-NEXT: )
;; CHECK-NEXT: (drop
;; CHECK-NEXT: (i64.ne
;; CHECK-NEXT: (local.get $y)
;; CHECK-NEXT: (i64.const 9223372036854775807)
;; CHECK-NEXT: )
;; CHECK-NEXT: )
;; CHECK-NEXT: (drop
;; CHECK-NEXT: (i32.ne
;; CHECK-NEXT: (local.get $x)
;; CHECK-NEXT: (i32.const -1)
;; CHECK-NEXT: )
;; CHECK-NEXT: )
;; CHECK-NEXT: (drop
;; CHECK-NEXT: (i64.ne
;; CHECK-NEXT: (local.get $y)
;; CHECK-NEXT: (i64.const -1)
;; CHECK-NEXT: )
;; CHECK-NEXT: )
;; CHECK-NEXT: (drop
;; CHECK-NEXT: (i32.eq
;; CHECK-NEXT: (local.get $x)
;; CHECK-NEXT: (i32.const -1)
;; CHECK-NEXT: )
;; CHECK-NEXT: )
;; CHECK-NEXT: (drop
;; CHECK-NEXT: (i64.eq
;; CHECK-NEXT: (local.get $y)
;; CHECK-NEXT: (i64.const -1)
;; CHECK-NEXT: )
;; CHECK-NEXT: )
;; CHECK-NEXT: )
(func $canonicalize-cmp-near-min-max (param $x i32) (param $y i64)
;; (signed)x < s_min + 1 ==> x == s_min
(drop (i32.lt_s
(local.get $x)
(i32.const -2147483647)
))
(drop (i64.lt_s
(local.get $y)
(i64.const -9223372036854775807)
))
;; (signed)x >= s_min + 1 ==> x != s_min
(drop (i32.ge_s
(local.get $x)
(i32.const -2147483647)
))
(drop (i64.ge_s
(local.get $y)
(i64.const -9223372036854775807)
))
;; (signed)x > s_max - 1 ==> x == s_max
(drop (i32.gt_s
(local.get $x)
(i32.const 2147483646)
))
(drop (i64.gt_s
(local.get $y)
(i64.const 9223372036854775806)
))
;; (signed)x <= s_max - 1 ==> x != s_max
(drop (i32.le_s
(local.get $x)
(i32.const 2147483646)
))
(drop (i64.le_s
(local.get $y)
(i64.const 9223372036854775806)
))
;; (unsigned)x <= u_max - 1 ==> x == u_max
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@kripken kripken Aug 29, 2022

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The text here is wrong, == should be != (but the optimizer output is right).

Same in the comment below, != should be ==.

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@MaxGraey MaxGraey Aug 29, 2022

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Thanks! Good catch. Do you want a separate PR which fix this comment or just append this minor fix with some other existing PR?

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@kripken kripken Aug 30, 2022

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A separate PR might be simplest. I am not up to date on the other PRs and am not sure when they will land. A separate PR can be landed immediately.

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@MaxGraey MaxGraey Aug 30, 2022

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#4992

(drop (i32.le_u
(local.get $x)
(i32.const -2)
))
(drop (i64.le_u
(local.get $y)
(i64.const -2)
))
;; (unsigned)x > u_max - 1 ==> x != u_max
(drop (i32.gt_u
(local.get $x)
(i32.const -2)
))
(drop (i64.gt_u
(local.get $y)
(i64.const -2)
))
)
;; CHECK: (func $canonicalize-cmp-const (param $x i32) (param $fx f64)
;; CHECK-NEXT: (drop
;; CHECK-NEXT: (i32.le_s
Expand Down
2 changes: 1 addition & 1 deletion test/lit/wat-kitchen-sink.wast
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Expand Up @@ -9,7 +9,7 @@

;; CHECK: (type $i32_=>_none (func_subtype (param i32) func))

;; CHECK: (rec
;; CHECK: (rec
;; CHECK-NEXT: (type $s0 (struct_subtype data))
(type $s0 (sub (struct)))
;; CHECK: (type $s1 (struct_subtype data))
Expand Down