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// This file tests multi-value returns. It creates a chain of wasm functions
//
// fnStart -> fnMid0 -> fnMid1 -> fnMid2 -> fnMid3 -> fnEnd
//
// When run, fnStart creates 12 (or in the non-simd case, 8) random values, of
// various types. It then passes them to fnMid0. That reorders them and
// passes them on to fnMid1, etc, until they arrive at fnEnd.
//
// fnEnd makes a small and reversible change to each value. It then reorders
// them and returns all of them. The returned values get passed back along
// the chain, being randomly reordered at each step, until they arrive back at
// fnStart.
//
// fnStart backs out the changes made in fnEnd and checks that the resulting
// values are the same as the originals it created. If they are not, the test
// has failed.
//
// If the test passes, we can be sure each value got passed along the chain
// and back again correctly, despite being in a probably different argument or
// return position each time (due to the reordering). As a side effect, this
// test also is a pretty good test of argument passing. The number of values
// (10) is chosen so as to be larger than the number of args that can be
// passed in regs on any target; hence it also tests the logic for passing
// args in regs vs memory too.
//
// The whole process (generate and run a test program) is repeated 120 times.
//
// Doing this requires some supporting functions to be defined in wasm, by
// `funcs_util` and `funcs_rng` (a random number generator).
//
// It is almost impossible to understand what the tests do by reading the JS
// below. Reading the generated wasm is required. Search for "if (0)" below.
// Some utility functions for use in the generated code.
function funcs_util(simdEnabled) {
let t =
(simdEnabled ?
`;; Create a v128 value from 2 i64 values
(func $v128_from_i64HL (export "v128_from_i64HL")
(param $i64hi i64) (param $i64lo i64) (result v128)
(local $vec v128)
(local.set $vec (i64x2.replace_lane 0 (local.get $vec) (local.get $i64lo)))
(local.set $vec (i64x2.replace_lane 1 (local.get $vec) (local.get $i64hi)))
(local.get $vec)
)
;; Split a v128 up into pieces.
(func $v128hi (export "v128hi") (param $vec v128) (result i64)
(return (i64x2.extract_lane 1 (local.get $vec)))
)
(func $v128lo (export "v128lo") (param $vec v128) (result i64)
(return (i64x2.extract_lane 0 (local.get $vec)))
)
;; Return an i32 value, which is 0 if the args are identical and 1 otherwise.
(func $v128ne (export "v128ne")
(param $vec1 v128) (param $vec2 v128) (result i32)
(return (v128.any_true (v128.xor (local.get $vec1) (local.get $vec2))))
)`
: ``/* simd not enabled*/
) +
`;; Move an i32 value forwards and backwards.
(func $step_i32 (export "step_i32") (param $n i32) (result i32)
(return (i32.add (local.get $n) (i32.const 1337)))
)
(func $unstep_i32 (export "unstep_i32") (param $n i32) (result i32)
(return (i32.sub (local.get $n) (i32.const 1337)))
)
;; Move an i64 value forwards and backwards.
(func $step_i64 (export "step_i64") (param $n i64) (result i64)
(return (i64.add (local.get $n) (i64.const 4771)))
)
(func $unstep_i64 (export "unstep_i64") (param $n i64) (result i64)
(return (i64.sub (local.get $n) (i64.const 4771)))
)
;; Move a f32 value forwards and backwards. This is a bit tricky because
;; we need to guarantee that the backwards move exactly cancels out the
;; forward move. So we multiply/divide exactly by 2 on the basis that that
;; will change the exponent but not the mantissa, at least for normalised
;; numbers.
(func $step_f32 (export "step_f32") (param $n f32) (result f32)
(return (f32.mul (local.get $n) (f32.const 2.0)))
)
(func $unstep_f32 (export "unstep_f32") (param $n f32) (result f32)
(return (f32.div (local.get $n) (f32.const 2.0)))
)
;; Move a f64 value forwards and backwards.
(func $step_f64 (export "step_f64") (param $n f64) (result f64)
(return (f64.mul (local.get $n) (f64.const 4.0)))
)
(func $unstep_f64 (export "unstep_f64") (param $n f64) (result f64)
(return (f64.div (local.get $n) (f64.const 4.0)))
)`
+ (simdEnabled ?
`;; Move a v128 value forwards and backwards.
(func $step_v128 (export "step_v128") (param $vec v128) (result v128)
(return (call $v128_from_i64HL
(i64.add (call $v128hi (local.get $vec)) (i64.const 1234))
(i64.add (call $v128lo (local.get $vec)) (i64.const 4321))
))
)
(func $unstep_v128 (export "unstep_v128") (param $vec v128) (result v128)
(return (call $v128_from_i64HL
(i64.sub (call $v128hi (local.get $vec)) (i64.const 1234))
(i64.sub (call $v128lo (local.get $vec)) (i64.const 4321))
))
)`
: ``/* simd not enabled*/
);
return t;
}
// A Pseudo-RNG based on the C standard. The core function generates only 16
// random bits. We have to use it twice to generate a 32-bit random number
// and four times for a 64-bit random number.
let decls_rng =
`;; The RNG's state
(global $rand_state
(mut i32) (i32.const 1)
)`;
function funcs_rng(simdEnabled) {
let t =
`;; Set the seed
(func $rand_setSeed (param $seed i32)
(global.set $rand_state (local.get $seed))
)
;; Generate a 16-bit random number
(func $rand_i16 (export "rand_i16") (result i32)
(local $t i32)
;; update $rand_state
(local.set $t (global.get $rand_state))
(local.set $t (i32.mul (local.get $t) (i32.const 1103515245)))
(local.set $t (i32.add (local.get $t) (i32.const 12345)))
(global.set $rand_state (local.get $t))
;; pull 16 random bits out of it
(local.set $t (i32.shr_u (local.get $t) (i32.const 15)))
(local.set $t (i32.and (local.get $t) (i32.const 0xFFFF)))
(local.get $t)
)
;; Generate a 32-bit random number
(func $rand_i32 (export "rand_i32") (result i32)
(local $t i32)
(local.set $t (call $rand_i16))
(local.set $t (i32.shl (local.get $t) (i32.const 16)))
(local.set $t (i32.or (local.get $t) (call $rand_i16)))
(local.get $t)
)
;; Generate a 64-bit random number
(func $rand_i64 (export "rand_i64") (result i64)
(local $t i64)
(local.set $t (i64.extend_i32_u (call $rand_i16)))
(local.set $t (i64.shl (local.get $t) (i64.const 16)))
(local.set $t (i64.or (local.get $t) (i64.extend_i32_u (call $rand_i16))))
(local.set $t (i64.shl (local.get $t) (i64.const 16)))
(local.set $t (i64.or (local.get $t) (i64.extend_i32_u (call $rand_i16))))
(local.set $t (i64.shl (local.get $t) (i64.const 16)))
(local.set $t (i64.or (local.get $t) (i64.extend_i32_u (call $rand_i16))))
(local.get $t)
)
;; Generate a 32-bit random float. This is something of a kludge in as much
;; as it does it by converting a random signed-int32 to a float32, which
;; means that we don't get any NaNs, infinities, denorms, etc, but OTOH
;; there's somewhat less randomness then there would be if we had allowed
;; such denorms in.
(func $rand_f32 (export "rand_f32") (result f32)
(f32.convert_i32_s (call $rand_i32))
)
;; And similarly for 64-bit random floats
(func $rand_f64 (export "rand_f64") (result f64)
(f64.convert_i64_s (call $rand_i64))
)`
+ (simdEnabled ?
`;; Generate a random 128-bit vector.
(func $rand_v128 (export "rand_v128") (result v128)
(call $v128_from_i64HL (call $rand_i64) (call $rand_i64))
)`
: ``/* simd not enabled*/
);
return t;
}
// Helpers for function generation
function strcmp(s1,s2) {
if (s1 < s2) return -1;
if (s1 > s2) return 1;
return 0;
}
// This generates the last function in the chain. It merely returns its
// arguments in a different order, but first applies the relevant `_step`
// function to each value. This is the only place in the process where
// the passed/return values are modified. Hence it gives us a way to be
// sure that the values made it all the way from the start function to the
// end of the chain (here) and back to the start function. Back in the
// start function, we will apply the relevant `_unstep` function to each
// returned value, which should give the value that was sent up the chain
// originally.
//
// Here and below, the following naming scheme is used:
//
// * taIn -- types of arguments that come in to this function
// * taOut -- types of arguments that this function passes
// to the next in the chain
// * trOut -- types of results that this function returns
// * trIn -- types of results that the next function in the chain
// returns to this function
//
// Hence 'a' vs 'r' distinguishes argument from return types, and 'In' vs
// 'Out' distinguishes values coming "in" to the function from those going
// "out". The 'a'/'r' naming scheme is also used in the generated wasm (text).
function genEnd(myFuncName, taIn, trOut) {
assertEq(taIn.length, trOut.length);
let params = taIn.map(pair => `(param $a${pair.name} ${pair.type})`)
.join(` `);
let retTys = trOut.map(pair => pair.type).join(` `);
let t =
`(func $${myFuncName} (export "${myFuncName}") ` +
` ${params} (result ${retTys})\n` +
trOut.map(pair =>
` (call $step_${pair.type} (local.get $a${pair.name}))`)
.join(`\n`) + `\n` +
`)`;
return t;
}
// This generates an intermediate function in the chain. It takes args as
// specified by `taIn`, rearranges them to match `taOut`, passes those to the
// next function in the chain. From which it receives return values as
// described by `trIn`, which it rearranges to match `trOut`, and returns
// those. Overall, then, it permutes values both in the calling direction and
// in the returning direction.
function genMiddle(myFuncName, nextFuncName, taIn, trOut, taOut, trIn) {
assertEq(taIn.length, taOut.length);
assertEq(taIn.length, trIn.length);
assertEq(taIn.length, trOut.length);
let params = taIn.map(pair => `(param $a${pair.name} ${pair.type})`)
.join(` `);
let retTys = trOut.map(pair => pair.type).join(` `);
let trInSorted = trIn.toSorted((p1,p2) => strcmp(p1.name,p2.name));
let t =
`(func $${myFuncName} (export "${myFuncName}") ` +
` ${params} (result ${retTys})\n` +
// Declare locals
trInSorted
.map(pair => ` (local $r${pair.name} ${pair.type})`)
.join(`\n`) + `\n` +
// Make the call
` (call $${nextFuncName} ` +
taOut.map(pair => `(local.get $a${pair.name})`).join(` `) + `)\n` +
// Capture the returned values
trIn.toReversed()
.map(pair => ` (local.set $r${pair.name})`).join(`\n`) + `\n` +
// Return
` (return ` + trOut.map(pair => `(local.get $r${pair.name})`)
.join (` `) + `)\n` +
`)`;
return t;
}
// This generates the first function in the chain. It creates random values
// for the initial arguments, passes them to the next arg in the chain,
// receives results, and checks that the results are as expected.
// NOTE! The generated function returns zero on success, non-zero on failure.
function genStart(myFuncName, nextFuncName, taOut, trIn) {
assertEq(taOut.length, trIn.length);
let taOutSorted = taOut.toSorted((p1,p2) => strcmp(p1.name,p2.name));
let trInSorted = trIn.toSorted((p1,p2) => strcmp(p1.name,p2.name));
// `taOutSorted` and `trInSorted` should be identical.
assertEq(taOutSorted.length, trInSorted.length);
for (let i = 0; i < taOutSorted.length; i++) {
assertEq(taOutSorted[i].name, trInSorted[i].name);
assertEq(taOutSorted[i].type, trInSorted[i].type);
}
let t =
`(func $${myFuncName} (export "${myFuncName}") (result i32)\n` +
// Declare locals
taOutSorted
.map(pair => ` (local $a${pair.name} ${pair.type})`)
.join(`\n`) + `\n` +
trInSorted
.map(pair => ` (local $r${pair.name} ${pair.type})`)
.join(`\n`) + `\n` +
` (local $anyNotEqual i32)\n` +
// Set up the initial values to be fed up the chain of calls and back
// down again. We expect them to be the same when they finally arrive
// back. Note we re-initialise the (wasm-side) RNG even though this
// isn't actually necessary.
` (call $rand_setSeed (i32.const 1))\n` +
taOutSorted
.map(pair => ` (local.set $a${pair.name} (call $rand_${pair.type}))`)
.join(`\n`) + `\n` +
// Actually make the call
` (call $${nextFuncName} ` +
taOut.map(pair => `(local.get $a${pair.name})`).join(` `) + `)\n` +
// Capture the returned values
trIn.toReversed()
.map(pair => ` (local.set $r${pair.name})`).join(`\n`) + `\n` +
// For each returned value, apply the relevant `_unstep` function,
// then compare it against the original. It should be the same, so
// accumulate any signs of difference in $anyNotEqual. Since
// `taOutSorted` and `trInSorted` are identical we can iterate over
// either.
taOutSorted
.map(pair =>
` (local.set $anyNotEqual \n` +
` (i32.or (local.get $anyNotEqual)\n` +
` (` +
// v128 doesn't have a suitable .ne operator, so call a helper fn
(pair.type === `v128` ? `call $v128ne` : `${pair.type}.ne`) +
` (local.get $a${pair.name})` +
` (call $unstep_${pair.type} (local.get $r${pair.name})))))`
)
.join(`\n`) + `\n` +
` (return (local.get $anyNotEqual))\n` +
`)`;
return t;
}
// A pseudo-random number generator that is independent of the one baked into
// each wasm program generated. This is for use in JS only. It isn't great,
// but at least it starts from a fixed place, which Math.random doesn't. This
// produces a function `rand4js`, which takes an argument `n` and produces an
// integer value in the range `0 .. n-1` inclusive. `n` needs to be less than
// or equal to 2^21 for this to work at all, and it needs to be much less than
// 2^21 (say, no more than 2^14) in order to get a reasonably even
// distribution of the values generated.
let rand4js_txt =
`(module
(global $rand4js_state (mut i32) (i32.const 1))
(func $rand4js (export "rand4js") (param $maxPlus1 i32) (result i32)
(local $t i32)
;; update $rand4js_state
(local.set $t (global.get $rand4js_state))
(local.set $t (i32.mul (local.get $t) (i32.const 1103515245)))
(local.set $t (i32.add (local.get $t) (i32.const 12345)))
(global.set $rand4js_state (local.get $t))
;; Note, the low order bits are not very random. Hence we dump the
;; low-order 11 bits. This leaves us with at best 21 usable bits.
(local.set $t (i32.shr_u (local.get $t) (i32.const 11)))
(i32.rem_u (local.get $t) (local.get $maxPlus1))
)
)`;
let rand4js = new WebAssembly.Instance(
new WebAssembly.Module(wasmTextToBinary(rand4js_txt)))
.exports.rand4js;
// Fisher-Yates scheme for generating random permutations of a sequence.
// Result is a new array containing the original items in a different order.
// Original is unchanged.
function toRandomPermutation(input) {
let n = input.length;
let result = input.slice();
assertEq(result.length, n);
if (n < 2) return result;
for (let i = 0; i < n - 1; i++) {
let j = i + rand4js(n - i);
let t = result[i];
result[i] = result[j];
result[j] = t;
}
return result;
}
// Top level test runner
function testMain(numIters) {
// Check whether we can use SIMD.
let simdEnabled = wasmSimdEnabled();
// Names tagged with types. This is set up to provide 10 values that
// potentially can be passed in integer registers (5 x i32, 5 x i64) and
// 10 values that potentially can be passed in FP/SIMD registers (3 x f32,
// 3 x f64, 4 x v128). This should cover both sides of the
// arg-passed-in-reg/arg-passed-in-mem boundary for all of the primary
// targets.
let val0 = {name: "0", type: "i32"};
let val1 = {name: "1", type: "i32"};
let val2 = {name: "2", type: "i32"};
let val3 = {name: "3", type: "i32"};
let val4 = {name: "4", type: "i32"};
let val5 = {name: "5", type: "i64"};
let val6 = {name: "6", type: "i64"};
let val7 = {name: "7", type: "i64"};
let val8 = {name: "8", type: "i64"};
let val9 = {name: "9", type: "i64"};
let vala = {name: "a", type: "f32"};
let valb = {name: "b", type: "f32"};
let valc = {name: "c", type: "f32"};
let vald = {name: "d", type: "f64"};
let vale = {name: "e", type: "f64"};
let valf = {name: "f", type: "f64"};
let valg = {name: "g", type: "v128"};
let valh = {name: "h", type: "v128"};
let vali = {name: "i", type: "v128"};
let valj = {name: "j", type: "v128"};
// This is the base name/type vector,
// of which we will create random permutations.
let baseValVec;
if (simdEnabled) {
baseValVec
= [val0, val1, val2, val3, val4, val5, val6, val7, val8, val9,
vala, valb, valc, vald, vale, valf, valg, valh, vali, valj];
} else {
baseValVec
= [val0, val1, val2, val3, val4, val5, val6, val7, val8, val9,
vala, valb, valc, vald, vale, valf];
}
function summariseVec(valVec) {
return valVec.map(pair => pair.name).join("");
}
print("\nsimdEnabled = " + simdEnabled + "\n");
for (let testRun = 0; testRun < numIters; testRun++) {
let tx0a = toRandomPermutation(baseValVec);
let tx0r = toRandomPermutation(baseValVec);
let tx1a = toRandomPermutation(baseValVec);
let tx1r = toRandomPermutation(baseValVec);
let tx2a = toRandomPermutation(baseValVec);
let tx2r = toRandomPermutation(baseValVec);
let tx3a = toRandomPermutation(baseValVec);
let tx3r = toRandomPermutation(baseValVec);
let tx4a = toRandomPermutation(baseValVec);
let tx4r = toRandomPermutation(baseValVec);
// Generate a 5-step chain of functions, each one passing and
// returning different permutation of `baseValVec`. The chain is:
// fnStart -> fnMid0 -> fnMid1 -> fnMid2 -> fnMid3 -> fnEnd
let t_end = genEnd("fnEnd", tx4a, tx4r);
let t_mid3 = genMiddle("fnMid3", "fnEnd", tx3a, tx3r, tx4a, tx4r);
let t_mid2 = genMiddle("fnMid2", "fnMid3", tx2a, tx2r, tx3a, tx3r);
let t_mid1 = genMiddle("fnMid1", "fnMid2", tx1a, tx1r, tx2a, tx2r);
let t_mid0 = genMiddle("fnMid0", "fnMid1", tx0a, tx0r, tx1a, tx1r);
let t_start = genStart("fnStart", "fnMid0", tx0a, tx0r);
let txt = "(module (memory 1) " + "\n" +
decls_rng + "\n" +
funcs_util(simdEnabled) + "\n" + funcs_rng(simdEnabled) + "\n" +
t_end + "\n" +
t_mid3 + "\n" + t_mid2 + "\n" + t_mid1 + "\n" + t_mid0 + "\n" +
t_start + "\n" +
")";
if (0) print(txt);
let mod = new WebAssembly.Module(wasmTextToBinary(txt));
let ins = new WebAssembly.Instance(mod);
let fns = ins.exports;
// result == 0 means success, any other value means failure
let result = fns.fnStart();
if (/*failure*/result != 0 || (testRun % 120) == 0)
print(" " + testRun + " " +
[tx0a,tx0r,tx1a,tx1r,tx2a,tx2r,tx3a,tx3r,tx4a,tx4r]
.map(e => summariseVec(e)).join("/") + " "
+ (result == 0 ? "pass" : "FAIL"));
assertEq(result, 0);
}
}
testMain(/*numIters=*/120);