From 9907ad6ed9fde5ccdb58a7d59d652a4c8a98a346 Mon Sep 17 00:00:00 2001 From: Mark Rousskov Date: Fri, 17 Apr 2020 21:42:22 -0400 Subject: Define UB in float-to-int casts to saturate - Round to zero, and representable values cast directly. - `NaN` goes to 0 - Values beyond the limits of the type are saturated to the "nearest value" (essentially rounding to zero, in some sense) in the integral type, so e.g. `f32::INFINITY` would go to `{u,i}N::MAX.` --- src/test/codegen/unchecked-float-casts.rs | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'src/test/codegen') diff --git a/src/test/codegen/unchecked-float-casts.rs b/src/test/codegen/unchecked-float-casts.rs index 34e96122223..789feea12d6 100644 --- a/src/test/codegen/unchecked-float-casts.rs +++ b/src/test/codegen/unchecked-float-casts.rs @@ -1,7 +1,7 @@ -// compile-flags: -C no-prepopulate-passes +// This file tests that we don't generate any code for saturation when using the +// unchecked intrinsics. -// This file tests that we don't generate any code for saturation if -// -Z saturating-float-casts is not enabled. +// compile-flags: -C opt-level=3 #![crate_type = "lib"] @@ -12,7 +12,7 @@ pub fn f32_to_u32(x: f32) -> u32 { // CHECK-NOT: fcmp // CHECK-NOT: icmp // CHECK-NOT: select - x as u32 + unsafe { x.to_int_unchecked() } } // CHECK-LABEL: @f32_to_i32 @@ -22,7 +22,7 @@ pub fn f32_to_i32(x: f32) -> i32 { // CHECK-NOT: fcmp // CHECK-NOT: icmp // CHECK-NOT: select - x as i32 + unsafe { x.to_int_unchecked() } } #[no_mangle] @@ -31,5 +31,5 @@ pub fn f64_to_u16(x: f64) -> u16 { // CHECK-NOT: fcmp // CHECK-NOT: icmp // CHECK-NOT: select - x as u16 + unsafe { x.to_int_unchecked() } } -- cgit 1.4.1-3-g733a5