> > After this patch (r245151), I've noticed regressions on aarch64: > gcc.target/aarch64/test_frame_1.c scan-assembler-times ldr\tx30, > \\[sp\\], [0-9]+ 2 > gcc.target/aarch64/test_frame_2.c scan-assembler-times ldp\tx19, > x30, \\[sp\\], [0-9]+ 1 > gcc.target/aarch64/test_frame_4.c scan-assembler-times ldp\tx19, > x30, \\[sp\\], [0-9]+ 1 > gcc.target/aarch64/test_frame_6.c scan-assembler-times ldr\tx30, \\[sp\\] 2 > gcc.target/aarch64/test_frame_7.c scan-assembler-times ldp\tx19, > x30, \\[sp\\] 1 > > now FAIL. > > For instance in test_frame_1.c, we used to generate: > ccmp w2, w1, 0, eq > bne .L6 > ldrb w0, [sp, 123] > ldrb w1, [sp, 124] > cmp w0, 99 > ccmp w1, w0, 0, eq > cset w0, eq > .L6: > ldr x30, [sp], 224 > ret > > and now: > ccmp w2, w1, 0, eq > beq .L11 > ldr x30, [sp], 224 > ret > .p2align 3 > .L11: > ldrb w0, [sp, 123] > ldrb w1, [sp, 124] > cmp w0, 99 > ldr x30, [sp], 224 > ccmp w1, w0, 0, eq > cset w0, eq > ret > > which is 2 instructions more, as the control flow is less efficient. > > Do we want to just update the tests (increasing the number of expected > str/ldr/stp/ldp to match the new code generation), or do we > consider this a regression caused by this patch?
I think it is not a regression, just the testcase if fragile and depends on outcome of ifcombine. It seems it was updated several time in the past. I am not quite sure what the test is testing, but probably just updating the testcase and/or disabling the ifconvert pass for it is the right answer. Honza
