diff options
| -rw-r--r-- | src/tools/miri/src/shims/x86/sse2.rs | 54 |
1 files changed, 27 insertions, 27 deletions
diff --git a/src/tools/miri/src/shims/x86/sse2.rs b/src/tools/miri/src/shims/x86/sse2.rs index 28aebc8cba8..b68690a835c 100644 --- a/src/tools/miri/src/shims/x86/sse2.rs +++ b/src/tools/miri/src/shims/x86/sse2.rs @@ -88,8 +88,8 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> { this.write_immediate(res, &dest)?; } } - // Used to implement the _mm_mulhi_epi16 function. - "pmulh.w" => { + // Used to implement the _mm_mulhi_epi16 and _mm_mulhi_epu16 functions. + "pmulh.w" | "pmulhu.w" => { let [left, right] = this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?; @@ -101,35 +101,35 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> { assert_eq!(dest_len, right_len); for i in 0..dest_len { - let left = this.read_scalar(&this.project_index(&left, i)?)?.to_i16()?; - let right = this.read_scalar(&this.project_index(&right, i)?)?.to_i16()?; + let left = this.read_immediate(&this.project_index(&left, i)?)?; + let right = this.read_immediate(&this.project_index(&right, i)?)?; let dest = this.project_index(&dest, i)?; - // Values are expanded from i16 to i32, so multiplication cannot overflow. - let res = i32::from(left).checked_mul(i32::from(right)).unwrap() >> 16; - this.write_scalar(Scalar::from_i16(res.try_into().unwrap()), &dest)?; - } - } - // Used to implement the _mm_mulhi_epu16 function. - "pmulhu.w" => { - let [left, right] = - this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?; - - let (left, left_len) = this.operand_to_simd(left)?; - let (right, right_len) = this.operand_to_simd(right)?; - let (dest, dest_len) = this.place_to_simd(dest)?; - - assert_eq!(dest_len, left_len); - assert_eq!(dest_len, right_len); + // Widen the operands to avoid overflow + let twice_wide_ty = this.get_twice_wide_int_ty(left.layout.ty); + let twice_wide_layout = this.layout_of(twice_wide_ty)?; + let left = this.int_to_int_or_float(&left, twice_wide_ty)?; + let right = this.int_to_int_or_float(&right, twice_wide_ty)?; - for i in 0..dest_len { - let left = this.read_scalar(&this.project_index(&left, i)?)?.to_u16()?; - let right = this.read_scalar(&this.project_index(&right, i)?)?.to_u16()?; - let dest = this.project_index(&dest, i)?; + // Multiply + let (multiplied, _overflow, _ty) = this.overflowing_binary_op( + mir::BinOp::Mul, + &ImmTy::from_immediate(left, twice_wide_layout), + &ImmTy::from_immediate(right, twice_wide_layout), + )?; + // Keep the high half + let (high, _overflow, _ty) = this.overflowing_binary_op( + mir::BinOp::Shr, + &ImmTy::from_scalar(multiplied, twice_wide_layout), + &ImmTy::from_uint(dest.layout.size.bits(), twice_wide_layout), + )?; - // Values are expanded from u16 to u32, so multiplication cannot overflow. - let res = u32::from(left).checked_mul(u32::from(right)).unwrap() >> 16; - this.write_scalar(Scalar::from_u16(res.try_into().unwrap()), &dest)?; + // Narrow back to the original type + let res = this.int_to_int_or_float( + &ImmTy::from_scalar(high, twice_wide_layout), + dest.layout.ty, + )?; + this.write_immediate(res, &dest)?; } } // Used to implement the _mm_mul_epu32 function. |