From 859e95abb84b67a2cb42d6e6013c16160d9c802d Mon Sep 17 00:00:00 2001 From: Segher Boessenkool Date: Wed, 12 Oct 2016 17:37:20 +0200 Subject: [PATCH] shrink-wrap: Testcases for separate shrink-wrapping A few testcases for separate shrink-wrapping: test whether it works in a trivial case; whether it creates more than one prologue where that is useful; whether it puts prologues inside a loop if that is cheaper. gcc/testsuite/ * gcc.target/powerpc/shrink-wrap-separate-0.c: New testcase. * gcc.target/powerpc/shrink-wrap-separate-1.c: New testcase. * gcc.target/powerpc/shrink-wrap-separate-2.c: New testcase. From-SVN: r241066 --- gcc/testsuite/ChangeLog | 6 +++++ .../powerpc/shrink-wrap-separate-0.c | 22 ++++++++++++++++ .../powerpc/shrink-wrap-separate-1.c | 18 +++++++++++++ .../powerpc/shrink-wrap-separate-2.c | 26 +++++++++++++++++++ 4 files changed, 72 insertions(+) create mode 100644 gcc/testsuite/gcc.target/powerpc/shrink-wrap-separate-0.c create mode 100644 gcc/testsuite/gcc.target/powerpc/shrink-wrap-separate-1.c create mode 100644 gcc/testsuite/gcc.target/powerpc/shrink-wrap-separate-2.c diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 4aed4b81d2e..5eb693a652f 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,9 @@ +2016-10-12 Segher Boessenkool + + * gcc.target/powerpc/shrink-wrap-separate-0.c: New testcase. + * gcc.target/powerpc/shrink-wrap-separate-1.c: New testcase. + * gcc.target/powerpc/shrink-wrap-separate-2.c: New testcase. + 2016-10-12 Segher Boessenkool * gcc.target/powerpc/warn-1.c: Change line number in dg-warning. diff --git a/gcc/testsuite/gcc.target/powerpc/shrink-wrap-separate-0.c b/gcc/testsuite/gcc.target/powerpc/shrink-wrap-separate-0.c new file mode 100644 index 00000000000..dea0611e8fc --- /dev/null +++ b/gcc/testsuite/gcc.target/powerpc/shrink-wrap-separate-0.c @@ -0,0 +1,22 @@ +/* { dg-do compile { target powerpc*-*-* } } */ +/* { dg-options "-O2" } */ +/* { dg-final { scan-assembler {#before\M.*\mmflr\M} } } */ + +/* This tests if shrink-wrapping for separate components works. + + r20 (a callee-saved register) is forced live at the start, so that we + get it saved in a prologue at the start of the function. + The link register only needs to be saved if x is non-zero; without + separate shrink-wrapping it would however be saved in the one prologue. + The test tests if the mflr insn ends up behind the prologue. */ + +void g(void); + +void f(int x) +{ + register int r20 asm("20") = x; + asm("#before" : : "r"(r20)); + if (x) + g(); + asm(""); // no tailcall of g +} diff --git a/gcc/testsuite/gcc.target/powerpc/shrink-wrap-separate-1.c b/gcc/testsuite/gcc.target/powerpc/shrink-wrap-separate-1.c new file mode 100644 index 00000000000..735b606e66d --- /dev/null +++ b/gcc/testsuite/gcc.target/powerpc/shrink-wrap-separate-1.c @@ -0,0 +1,18 @@ +/* { dg-do compile { target powerpc*-*-* } } */ +/* { dg-options "-O2" } */ +/* { dg-final { scan-assembler {\mmflr\M.*\mbl\M.*\mmflr\M.*\mbl\M} } } */ + +/* This tests if shrink-wrapping for separate components creates more + than one prologue when that is useful. In this case, it saves the + link register before both the call to g and the call to h. */ + +void g(void) __attribute__((noreturn)); +void h(void) __attribute__((noreturn)); + +void f(int x) +{ + if (x == 42) + g(); + if (x == 31) + h(); +} diff --git a/gcc/testsuite/gcc.target/powerpc/shrink-wrap-separate-2.c b/gcc/testsuite/gcc.target/powerpc/shrink-wrap-separate-2.c new file mode 100644 index 00000000000..b22564a51c5 --- /dev/null +++ b/gcc/testsuite/gcc.target/powerpc/shrink-wrap-separate-2.c @@ -0,0 +1,26 @@ +/* { dg-do compile { target powerpc*-*-* } } */ +/* { dg-options "-O2" } */ +/* { dg-final { scan-assembler {\mmflr\M.*\mbl\M.*\mmflr\M.*\mbl\M} } } */ + +/* This tests if shrink-wrapping for separate components puts a prologue + inside a loop when that is useful. In this case, it saves the link + register before each call: both calls happen with probability .10, + so saving the link register happens with .80 per execution of f on + average, which is smaller than 1 which you would get if you saved + it outside the loop. */ + +int *a; +void g(void); + +void f(int x) +{ + int j; + for (j = 0; j < 4; j++) { + if (__builtin_expect(a[j], 0)) + g(); + asm("#" : : : "memory"); + if (__builtin_expect(a[j], 0)) + g(); + a[j]++; + } +} -- 2.30.2