1 ; This tests against a lowering error in a multiply instruction that produces 2 ; results in a low and high register. This is usually lowered as a mul 3 ; instruction whose dest contains the low portion, and a FakeDef of the high 4 ; portion. The problem is that if the high portion is unused (e.g. the multiply 5 ; is followed by a truncation), the FakeDef may be eliminated, and the register 6 ; allocator may assign the high register to a variable that is live across the 7 ; mul instruction. This is incorrect because the mul instruction smashes the 8 ; register. 9 10 ; REQUIRES: allow_dump 11 12 ; RUN: %p2i --target x8632 -i %s --filetype=asm --args -O2 -asm-verbose \ 13 ; RUN: --split-local-vars=0 \ 14 ; RUN: --reg-use=eax,edx -reg-reserve | FileCheck --check-prefix=X8632 %s 15 ; RUN: %p2i --target arm32 -i %s --filetype=asm --args -O2 -asm-verbose \ 16 ; RUN: | FileCheck --check-prefix=ARM32 %s 17 18 define internal i32 @mul(i64 %a, i64 %b, i32 %c) { 19 ; Force an early use of %c. 20 store i32 %c, i32* undef, align 1 21 %m = mul i64 %a, %b 22 %t = trunc i64 %m to i32 23 ; Make many uses of %c to give it high weight. 24 %t1 = add i32 %t, %c 25 %t2 = add i32 %t1, %c 26 %t3 = add i32 %t2, %c 27 ret i32 %t3 28 } 29 30 ; For x8632, we want asm-verbose to print the stack offset assignment for lv$c 31 ; ("local variable 'c'") in the prolog, and then have at least one use of lv$c 32 ; in the body, i.e. don't register-allocate edx to %c. 33 34 ; X8632-LABEL: mul 35 ; X8632: lv$c = 36 ; X8632: lv$c 37 38 ; For arm32, the failure would manifest as a translation error - no register 39 ; being allocated to the high operand, so we just check for successful 40 ; translation. 41 42 ; ARM32-LABEL: mul 43
