diff options
Diffstat (limited to 'src/wasm/literal.cpp')
| -rw-r--r-- | src/wasm/literal.cpp | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/src/wasm/literal.cpp b/src/wasm/literal.cpp index 29d047723..f0a065c45 100644 --- a/src/wasm/literal.cpp +++ b/src/wasm/literal.cpp @@ -868,6 +868,18 @@ Literal Literal::div(const Literal& other) const { case FP_INFINITE: // fallthrough case FP_NORMAL: // fallthrough case FP_SUBNORMAL: + // Special-case division by 1. nan / 1 can change nan bits per the + // wasm spec, but it is ok to just return that original nan, and we + // do that here so that we are consistent with the optimization of + // removing the / 1 and leaving just the nan. That is, if we just + // do a normal divide and the CPU decides to change the bits, we'd + // give a different result on optimized code, which would look like + // it was a bad optimization. So out of all the valid results to + // return here, return the simplest one that is consistent with + // optimization. + if (rhs == 1) { + return Literal(lhs); + } return Literal(lhs / rhs); default: WASM_UNREACHABLE("invalid fp classification"); @@ -896,6 +908,10 @@ Literal Literal::div(const Literal& other) const { case FP_INFINITE: // fallthrough case FP_NORMAL: // fallthrough case FP_SUBNORMAL: + // See above comment on f32. + if (rhs == 1) { + return Literal(lhs); + } return Literal(lhs / rhs); default: WASM_UNREACHABLE("invalid fp classification"); |