Bug 8497 – Regression 2.060: Bad code gen involving ubyte, ternary operators, and shifts

Sorry for the title, don't know how to describe this well: ------------------ class Foo { public: void foo(uint value) { ubyte size = value < (0x7fU << 0 ) ? 1 : value < (0x7fU << 14) ? 2 : 3; import std.stdio; writeln(size); } } void main() { Foo f = new Foo(); f.foo(1000000); } ------------------ With no optimisations or any other flags, this prints out 255, even though it should print 2. Happens in DMD 2.060, but not 2.059.

Dissassembly: _D4test3Foo3fooMFkZv: 00000001000007b0 pushq %rbp 00000001000007b1 movq %rsp,%rbp 00000001000007b4 subq $0x18,%rsp 00000001000007b8 pushq %rbx 00000001000007b9 movl %esi,0xf8(%rbp) 00000001000007bc testq %rdi,%rdi 00000001000007bf jne 0x1000007f6 00000001000007c1 movl $0x00000004,%r8d 00000001000007c7 movq 0x00022b5a(%rip),%rcx 00000001000007ce movq 0x00022b4b(%rip),%rax 00000001000007d5 movq %rax,%rdx 00000001000007d8 movq %rdx,0xe8(%rbp) 00000001000007dc movq 0x00022b65(%rip),%rdx 00000001000007e3 movq 0x00022b56(%rip),%rdi 00000001000007ea movq %rdx,%rsi 00000001000007ed movq 0xe8(%rbp),%rdx 00000001000007f1 callq 0x10002189a ; symbol stub for: __d_assert_msg 00000001000007f6 callq 0x1000217e0 ; symbol stub for: _D9invariant12_d_invariantFC6ObjectZv 00000001000007fb movl 0xf8(%rbp),%ebx 00000001000007fe cmpl $0x7f,%ebx 0000000100000801 movl $0x00000001,%esi 0000000100000806 jb 0x100000813 0000000100000808 cmpl $0x001fc000,%ebx 000000010000080e sbbl %esi,%esi 0000000100000810 addb $0x03,%dh 0000000100000813 movq %rsi,%rdi 0000000100000816 callq 0x100021282 ; symbol stub for: _D3std5stdio14__T7writelnThZ7writelnFhZv 000000010000081b popq %rbx 000000010000081c leave 000000010000081d ret

Same thing happens over here in Linux.

Commit pushed to dmd-1.x at https://github.com/D-Programming-Language/dmd https://github.com/D-Programming-Language/dmd/commit/9b3a8aa4e82a85d2392ad4e2c103157284c47665 fix Issue 8497 - Regression 2.060: Bad code gen involving ubyte, ternary operators, and shifts

Commit pushed to master at https://github.com/D-Programming-Language/dmd https://github.com/D-Programming-Language/dmd/commit/fa6c7fb523455743f29bb944100e3617de594cbc fix Issue 8497 - Regression 2.060: Bad code gen involving ubyte, ternary operators, and shifts

Not a regression, but fixed anyway.