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| author | Andrea Corallo <andrea.corallo@arm.com> | 2021-02-03 15:21:54 +0100 |
|---|---|---|
| committer | Andrea Corallo <andrea.corallo@arm.com> | 2021-02-11 16:20:59 +0100 |
| commit | 38c5703449c0638618ba6896f0d039c3868ad4e0 (patch) | |
| tree | 848c1145e85db131379e114b139a4ee3b648912d | |
| parent | 4af29981ab57ad7ef4467e371e4145cce9c16eaa (diff) | |
| download | gcc-38c5703449c0638618ba6896f0d039c3868ad4e0.zip gcc-38c5703449c0638618ba6896f0d039c3868ad4e0.tar.gz gcc-38c5703449c0638618ba6896f0d039c3868ad4e0.tar.bz2 | |
arm: Low overhead loop handle long range branches [PR98931]
gcc/
PR target/98931
* config/arm/thumb2.md (*doloop_end_internal): Generate
alternative sequence to handle long range branches.
gcc/testsuite/
PR target/98931
* gcc.target/arm/pr98931.c: New testcase.
| -rw-r--r-- | gcc/config/arm/thumb2.md | 28 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.target/arm/pr98931.c | 17 |
2 files changed, 37 insertions, 8 deletions
diff --git a/gcc/config/arm/thumb2.md b/gcc/config/arm/thumb2.md index bd53bf3..d7fd96c 100644 --- a/gcc/config/arm/thumb2.md +++ b/gcc/config/arm/thumb2.md @@ -1711,15 +1711,27 @@ ;; Originally expanded by 'doloop_end'. (define_insn "*doloop_end_internal" - [(parallel [(set (pc) - (if_then_else - (ne (reg:SI LR_REGNUM) (const_int 1)) - (label_ref (match_operand 0 "" "")) - (pc))) - (set (reg:SI LR_REGNUM) - (plus:SI (reg:SI LR_REGNUM) (const_int -1)))])] + [(set (pc) + (if_then_else + (ne (reg:SI LR_REGNUM) (const_int 1)) + (label_ref (match_operand 0 "" "")) + (pc))) + (set (reg:SI LR_REGNUM) + (plus:SI (reg:SI LR_REGNUM) (const_int -1))) + (clobber (reg:CC CC_REGNUM))] "TARGET_32BIT && TARGET_HAVE_LOB" - "le\t%|lr, %l0") + { + if (get_attr_length (insn) == 4) + return "le\t%|lr, %l0"; + else + return "subs\t%|lr, #1;bne\t%l0"; + } + [(set (attr "length") + (if_then_else + (ltu (minus (pc) (match_dup 0)) (const_int 1024)) + (const_int 4) + (const_int 6))) + (set_attr "type" "branch")]) (define_expand "doloop_begin" [(match_operand 0 "" "") diff --git a/gcc/testsuite/gcc.target/arm/pr98931.c b/gcc/testsuite/gcc.target/arm/pr98931.c new file mode 100644 index 0000000..313876a --- /dev/null +++ b/gcc/testsuite/gcc.target/arm/pr98931.c @@ -0,0 +1,17 @@ +/* { dg-do assemble } */ +/* { dg-skip-if "avoid conflicting multilib options" { *-*-* } { "-marm" "-mcpu=*" } } */ +/* { dg-options "-march=armv8.1-m.main -O3 --param=max-completely-peeled-insns=1300 --save-temps" } */ + +extern long long a[][20][26][26][22]; + +void +foo () +{ + for (short d = 0; d + 1; d++) + for (unsigned e = 0; e < 25; e += 4) + for (unsigned f = 0; f < 25; f += 4) + for (int g = 0; g < 21; g += 4) + a[4][d][e][f][g] = 0; +} + +/* { dg-final { scan-assembler-not {le\slr,\s\S*} } } */ |