Hi,
In GCC there is one useful option -dp (or -dP for more verbose output)
to annotate assembler with instruction patterns, that was used when
assembler was generated. For example:
double
test(long long s)
{
return s;
}
gcc -S -dp -O0 test.c
test:
.LFB0:
.cfi_startproc
pushq %rbp # 18 *pushdi2_rex64/1 [length = 1]
.cfi_def_cfa_offset 16
movq %rsp, %rbp # 19 *movdi_1_rex64/2 [length = 3]
.cfi_offset 6, -16
.cfi_def_cfa_register 6
movq %rdi, -8(%rbp) # 2 *movdi_1_rex64/4 [length = 4]
cvtsi2sdq -8(%rbp), %xmm0 # 6 *floatdidf2_sse_interunit/2 [length = 6]
leave # 24 leave_rex64 [length = 1]
.cfi_def_cfa 7, 8
ret # 25 return_internal [length = 1]
.cfi_endproc
Now I may look into config/i386/i386.md, and look for mentioned
*pushdi2_rex64, movdi_1_rex64, floatdidf2_sse_interunit and other
patterns and study how they work.
How to make the same annotation for clang output assembler code?
test:
.Leh_func_begin1:
pushq %rbp # ??? what insn in X86InstrInfo.td?
.Llabel1:
movq %rsp, %rbp # ??? what insn in X86InstrInfo.td?
.Llabel2:
movq %rdi, -16(%rbp) # ??? what insn in X86InstrInfo.td?
movq -16(%rbp), %rax # ??? what insn in X86InstrInfo.td?
cvtsi2sdq %rax, %xmm0 # ??? what insn in X86InstrInfo.td?
movsd %xmm0, -8(%rbp) # ??? what insn in X86InstrInfo.td?
movsd -8(%rbp), %xmm0 # ??? what insn in X86InstrInfo.td?
popq %rbp # ??? what insn in X86InstrInfo.td?
ret
---
With best regards, Konstantin
Hello> How to make the same annotation for clang output assembler code?There is no such functionality. -- With best regards, Anton Korobeynikov Faculty of Mathematics and Mechanics, Saint Petersburg State University
On 02.03.2012, at 09:20, Konstantin Vladimirov wrote:> Hi, > > In GCC there is one useful option -dp (or -dP for more verbose output) > to annotate assembler with instruction patterns, that was used when > assembler was generated. For example:The internal "-mllvm -show-mc-inst" option is probably as close as you can get. $ clang -S -O0 test.c -mllvm -show-mc-inst -o - _test: ## @test .cfi_startproc ## BB#0: ## %entry pushq %rbp ## <MCInst #2120 PUSH64r ## <MCOperand Reg:106>> Ltmp2: .cfi_def_cfa_offset 16 Ltmp3: .cfi_offset %rbp, -16 movq %rsp, %rbp ## <MCInst #1491 MOV64rr ## <MCOperand Reg:106> ## <MCOperand Reg:114>> Ltmp4: .cfi_def_cfa_register %rbp movq %rdi, -8(%rbp) ## <MCInst #1482 MOV64mr ## <MCOperand Reg:106> ## <MCOperand Imm:1> ## <MCOperand Reg:0> ## <MCOperand Imm:-8> ## <MCOperand Reg:0> ## <MCOperand Reg:109>> cvtsi2sdq -8(%rbp), %xmm0 ## <MCInst #607 CVTSI2SD64rm ## <MCOperand Reg:128> ## <MCOperand Reg:106> ## <MCOperand Imm:1> ## <MCOperand Reg:0> ## <MCOperand Imm:-8> ## <MCOperand Reg:0>> popq %rbp ## <MCInst #2000 POP64r ## <MCOperand Reg:106>> ret ## <MCInst #2227 RET> .cfi_endproc - Ben> > double > test(long long s) > { > return s; > } > > gcc -S -dp -O0 test.c > > test: > .LFB0: > .cfi_startproc > pushq %rbp # 18 *pushdi2_rex64/1 [length = 1] > .cfi_def_cfa_offset 16 > movq %rsp, %rbp # 19 *movdi_1_rex64/2 [length = 3] > .cfi_offset 6, -16 > .cfi_def_cfa_register 6 > movq %rdi, -8(%rbp) # 2 *movdi_1_rex64/4 [length = 4] > cvtsi2sdq -8(%rbp), %xmm0 # 6 *floatdidf2_sse_interunit/2 [length = 6] > leave # 24 leave_rex64 [length = 1] > .cfi_def_cfa 7, 8 > ret # 25 return_internal [length = 1] > .cfi_endproc > > Now I may look into config/i386/i386.md, and look for mentioned > *pushdi2_rex64, movdi_1_rex64, floatdidf2_sse_interunit and other > patterns and study how they work. > > How to make the same annotation for clang output assembler code? > > test: > .Leh_func_begin1: > pushq %rbp # ??? what insn in X86InstrInfo.td? > .Llabel1: > movq %rsp, %rbp # ??? what insn in X86InstrInfo.td? > .Llabel2: > movq %rdi, -16(%rbp) # ??? what insn in X86InstrInfo.td? > movq -16(%rbp), %rax # ??? what insn in X86InstrInfo.td? > cvtsi2sdq %rax, %xmm0 # ??? what insn in X86InstrInfo.td? > movsd %xmm0, -8(%rbp) # ??? what insn in X86InstrInfo.td? > movsd -8(%rbp), %xmm0 # ??? what insn in X86InstrInfo.td? > popq %rbp # ??? what insn in X86InstrInfo.td? > ret > > > --- > With best regards, Konstantin > _______________________________________________ > LLVM Developers mailing list > LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
Hi, Thank you, it is just what I need. But... it doesn't work for me: $ clang -S -O0 test.c -mllvm -show-mc-inst error: unknown argument: '-show-mc-inst' $ clang --version clang version 1.1 (branches/release_27) Target: x86_64-pc-linux-gnu Thread model: posix May be I need LLVM with higher version, or mention something in configure options? On Fri, Mar 2, 2012 at 4:32 PM, Benjamin Kramer <benny.kra at googlemail.com> wrote:> > On 02.03.2012, at 09:20, Konstantin Vladimirov wrote: > >> Hi, >> >> In GCC there is one useful option -dp (or -dP for more verbose output) >> to annotate assembler with instruction patterns, that was used when >> assembler was generated. For example: > > The internal "-mllvm -show-mc-inst" option is probably as close as you can get. > > $ clang -S -O0 test.c -mllvm -show-mc-inst -o - > _test: ## @test > .cfi_startproc > ## BB#0: ## %entry > pushq %rbp ## <MCInst #2120 PUSH64r > ## <MCOperand Reg:106>> > Ltmp2: > .cfi_def_cfa_offset 16 > Ltmp3: > .cfi_offset %rbp, -16 > movq %rsp, %rbp ## <MCInst #1491 MOV64rr > ## <MCOperand Reg:106> > ## <MCOperand Reg:114>> > Ltmp4: > .cfi_def_cfa_register %rbp > movq %rdi, -8(%rbp) ## <MCInst #1482 MOV64mr > ## <MCOperand Reg:106> > ## <MCOperand Imm:1> > ## <MCOperand Reg:0> > ## <MCOperand Imm:-8> > ## <MCOperand Reg:0> > ## <MCOperand Reg:109>> > cvtsi2sdq -8(%rbp), %xmm0 ## <MCInst #607 CVTSI2SD64rm > ## <MCOperand Reg:128> > ## <MCOperand Reg:106> > ## <MCOperand Imm:1> > ## <MCOperand Reg:0> > ## <MCOperand Imm:-8> > ## <MCOperand Reg:0>> > popq %rbp ## <MCInst #2000 POP64r > ## <MCOperand Reg:106>> > ret ## <MCInst #2227 RET> > .cfi_endproc > > - Ben > >> >> double >> test(long long s) >> { >> return s; >> } >> >> gcc -S -dp -O0 test.c >> >> test: >> .LFB0: >> .cfi_startproc >> pushq %rbp # 18 *pushdi2_rex64/1 [length = 1] >> .cfi_def_cfa_offset 16 >> movq %rsp, %rbp # 19 *movdi_1_rex64/2 [length = 3] >> .cfi_offset 6, -16 >> .cfi_def_cfa_register 6 >> movq %rdi, -8(%rbp) # 2 *movdi_1_rex64/4 [length = 4] >> cvtsi2sdq -8(%rbp), %xmm0 # 6 *floatdidf2_sse_interunit/2 [length = 6] >> leave # 24 leave_rex64 [length = 1] >> .cfi_def_cfa 7, 8 >> ret # 25 return_internal [length = 1] >> .cfi_endproc >> >> Now I may look into config/i386/i386.md, and look for mentioned >> *pushdi2_rex64, movdi_1_rex64, floatdidf2_sse_interunit and other >> patterns and study how they work. >> >> How to make the same annotation for clang output assembler code? >> >> test: >> .Leh_func_begin1: >> pushq %rbp # ??? what insn in X86InstrInfo.td? >> .Llabel1: >> movq %rsp, %rbp # ??? what insn in X86InstrInfo.td? >> .Llabel2: >> movq %rdi, -16(%rbp) # ??? what insn in X86InstrInfo.td? >> movq -16(%rbp), %rax # ??? what insn in X86InstrInfo.td? >> cvtsi2sdq %rax, %xmm0 # ??? what insn in X86InstrInfo.td? >> movsd %xmm0, -8(%rbp) # ??? what insn in X86InstrInfo.td? >> movsd -8(%rbp), %xmm0 # ??? what insn in X86InstrInfo.td? >> popq %rbp # ??? what insn in X86InstrInfo.td? >> ret >> >> >> --- >> With best regards, Konstantin >> _______________________________________________ >> LLVM Developers mailing list >> LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu >> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev >