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| author | Bernd Schmidt <bernds@redhat.com> | 2016-11-07 16:59:11 +0000 |
|---|---|---|
| committer | Bernd Schmidt <bernds@gcc.gnu.org> | 2016-11-07 16:59:11 +0000 |
| commit | caa024ffce186dc6ce7ee8217d5d50d7f9a091e0 (patch) | |
| tree | 72ba9cd88f9d252504f2834bfe31a6b5057882f5 /gcc/combine.c | |
| parent | b4ff394c548414d6594170573c1cea89b91968e1 (diff) | |
| download | gcc-caa024ffce186dc6ce7ee8217d5d50d7f9a091e0.zip gcc-caa024ffce186dc6ce7ee8217d5d50d7f9a091e0.tar.gz gcc-caa024ffce186dc6ce7ee8217d5d50d7f9a091e0.tar.bz2 | |
re PR tree-optimization/77309 (wrong code at -Os and above on x86_64-linux-gnu (in the 64-bit mode))
PR rtl-optimization/77309
* combine.c (make_compound_operation): Allow EQ for IN_CODE, and
don't assume an equality comparison for plain COMPARE.
(simplify_comparison): Pass a more accurate code to
make_compound_operation.
testsuite/
PR rtl-optimization/77309
* gcc.dg/torture/pr77309.c: New test.
From-SVN: r241912
Diffstat (limited to 'gcc/combine.c')
| -rw-r--r-- | gcc/combine.c | 24 |
1 files changed, 18 insertions, 6 deletions
diff --git a/gcc/combine.c b/gcc/combine.c index f772878..6902056 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -7753,7 +7753,8 @@ extract_left_shift (rtx x, int count) IN_CODE says what kind of expression we are processing. Normally, it is SET. In a memory address it is MEM. When processing the arguments of - a comparison or a COMPARE against zero, it is COMPARE. */ + a comparison or a COMPARE against zero, it is COMPARE, or EQ if more + precisely it is an equality comparison against zero. */ rtx make_compound_operation (rtx x, enum rtx_code in_code) @@ -7767,6 +7768,7 @@ make_compound_operation (rtx x, enum rtx_code in_code) rtx new_rtx = 0; rtx tem; const char *fmt; + bool equality_comparison = false; /* PR rtl-optimization/70944. */ if (VECTOR_MODE_P (mode)) @@ -7776,6 +7778,11 @@ make_compound_operation (rtx x, enum rtx_code in_code) address, we stay there. If we have a comparison, set to COMPARE, but once inside, go back to our default of SET. */ + if (in_code == EQ) + { + equality_comparison = true; + in_code = COMPARE; + } next_code = (code == MEM ? MEM : ((code == COMPARE || COMPARISON_P (x)) && XEXP (x, 1) == const0_rtx) ? COMPARE @@ -7984,11 +7991,12 @@ make_compound_operation (rtx x, enum rtx_code in_code) /* If we are in a comparison and this is an AND with a power of two, convert this into the appropriate bit extract. */ else if (in_code == COMPARE - && (i = exact_log2 (UINTVAL (XEXP (x, 1)))) >= 0) + && (i = exact_log2 (UINTVAL (XEXP (x, 1)))) >= 0 + && (equality_comparison || i < GET_MODE_PRECISION (mode) - 1)) new_rtx = make_extraction (mode, - make_compound_operation (XEXP (x, 0), - next_code), - i, NULL_RTX, 1, 1, 0, 1); + make_compound_operation (XEXP (x, 0), + next_code), + i, NULL_RTX, 1, 1, 0, 1); /* If the one operand is a paradoxical subreg of a register or memory and the constant (limited to the smaller mode) has only zero bits where @@ -12473,7 +12481,11 @@ simplify_comparison (enum rtx_code code, rtx *pop0, rtx *pop1) We can never remove a SUBREG for a non-equality comparison because the sign bit is in a different place in the underlying object. */ - op0 = make_compound_operation (op0, op1 == const0_rtx ? COMPARE : SET); + rtx_code op0_mco_code = SET; + if (op1 == const0_rtx) + op0_mco_code = code == NE || code == EQ ? EQ : COMPARE; + + op0 = make_compound_operation (op0, op0_mco_code); op1 = make_compound_operation (op1, SET); if (GET_CODE (op0) == SUBREG && subreg_lowpart_p (op0) |