ice: Don't know how to copy this physical register!

[regehr]

Bugzilla Link	3244
Resolution	FIXED
Resolved on	Jan 11, 2009 21:21
Version	unspecified
OS	Linux
CC	@isanbard,@sunfishcode

Extended Description

Seen using r61273 on Ubuntu Hardy on x86.

regehr@john-home:~/volatile/tmp81$ llvm-gcc -O2 small.c
cc1: ScheduleDAGRRList.cpp:781: void::ScheduleDAGRRList::ListScheduleBottomUp(): Assertion `false && "Don't know how to copy this physical register!"' failed.
small.c:20: internal compiler error: Aborted
Please submit a full bug report,
with preprocessed source if appropriate.
See URL:http://developer.apple.com/bugreporter for instructions.

regehr@john-home:~/volatile/tmp81$ cat small.c

typedef short int int16_t;
typedef char uint8_t;
typedef int uint32_t;
uint8_t
safe_mul_func_uint8_t_u_u (uint8_t _ui1, uint32_t _ui2)
{
return _ui1 * _ui2;
}

int16_t g_62;
uint32_t g_487;
uint32_t func_85 (int16_t p_86, uint32_t p_87, uint32_t p_88);
uint32_t
func_42 (uint32_t p_43, uint32_t p_44, uint32_t p_45, uint32_t p_46)
{
func_78 (func_85
(safe_mul_func_uint8_t_u_u
(func_7 (0xC22AAA77DD28626BLL, 1),
(-2147483647 - 1 ? g_487 : 1) * g_62), 1, 1), p_46, 1);
}

[isanbard]

Bugpoint reduced testcase:

@​g_62 = external global i16 ; <i16*> [#uses=1]
@​g_487 = external global i32 ; <i32*> [#uses=1]

define i32 @​func_42(i32 %p_43, i32 %p_44, i32 %p_45, i32 %p_46) nounwind {
entry:
%0 = load i16* @​g_62, align 2 ; [#uses=1]
%1 = load i32* @​g_487, align 4 ; [#uses=1]
%2 = trunc i16 %0 to i8 ; [#uses=1]
%3 = trunc i32 %1 to i8 ; [#uses=1]
%4 = tail call i32 (...)* @​func_7(i64 -4455561449541442965, i32 1) nounwind ; [#uses=1]
%5 = trunc i32 %4 to i8 ; [#uses=1]
%6 = mul i8 %3, %2 ; [#uses=1]
%7 = mul i8 %6, %5 ; [#uses=1]
%8 = sext i8 %7 to i16 ; [#uses=1]
%9 = tail call i32 @​func_85(i16 signext %8, i32 1, i32 1) nounwind ; [#uses=0]
ret i32 undef
}

declare i32 @​func_7(...)

declare i32 @​func_85(i16 signext, i32, i32)

[llvmbot]

Ah, the scheduler is not correctly handling physical register dependency of normal GPR registers.

[llvmbot]

Fixed.
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20090105/072022.html